MHC class I deficiency

Summary

MHC class I deficiency (MONDO:0011476) is a disease caused by variants in TAP1 and TAP2, with 7 cohort genes. The dominant Reactome pathway is ER-Phagosome pathway (5 cohort genes).

At a glance

• Prevalence: <1 / 1 000 000 (Worldwide) [Orphanet-validated]
• Causal genes: TAP1 (GenCC Definitive), TAP2 (GenCC Strong)
• Cohort genes: 7
• ClinVar variants: 1,223

Clinical features

Epidemiology

Prevalence records

2 prevalence record(s), Orphanet:

Type	Class	Value	Geography	Validation
Cases/families		30	Worldwide	Validated
Point prevalence	<1 / 1 000 000		Worldwide	Validated

Identifiers

Disease identifiers

Field	Value
Canonical name	MHC class I deficiency
Mondo ID	MONDO:0011476
OMIM	604571
Orphanet	34592
DOID	DOID:0060009
ICD-11	489749747
SNOMED CT	725136003
UMLS	C1858266
MedGen	346868
GARD	0009548
Is cancer (heuristic)	no

Also known as: Bare lymphocyte syndrome type 1 · BLS type 1 · immunodeficiency by defective expression of HLA class 1 · immunodeficiency by defective expression of HLA class type 1

Data availability: 1,223 ClinVar variants · 11 GenCC gene-disease records · 6 cell lines.

Disease family

An umbrella term covering 3 Mondo subtypes.

Classification path: disease › human disease › disease by etiologic mechanism › disease of genetic or genomic mechanism › hereditary disease › immunodeficiency disease › combined immunodeficiency › MHC class I deficiency

Related subtypes (32): ataxia telangiectasia, combined immunodeficiency due to ZAP70 deficiency, X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection and neoplasia, combined immunodeficiency due to moesin deficiency, Wiskott-Aldrich syndrome, combined immunodeficiency due to STK4 deficiency, combined immunodeficiency due to MALT1 deficiency, combined immunodeficiency due to OX40 deficiency, combined immunodeficiency due to CD3gamma deficiency, combined immunodeficiency due to CTPS1 deficiency, combined immunodeficiency due to CRAC channel dysfunction, severe combined immunodeficiency, non-SCID combined immunodeficiency, combined immunodeficiency due to RELA haploinsufficiency, combined immunodeficiency due to GINS1 deficiency, combined immunodeficiency syndrome, combined immunodeficiency due to POLE2 deficiency, autosomal recessive combined immunodeficiency due to complete IL6ST deficiency, autosomal recessive combined immunodeficiency due to partial IL6ST deficiency, autosomal dominant combined immunodeficiency due to partial IL6ST deficiency, autosomal recessive combined immunodeficiency due to IL6R deficiency, autosomal dominant combined immunodeficiency due to ERBIN deficiency, combined immunodeficiency due to TBX1 deficiency, RAC2-related combined immunodeficiency-bronchiectasis-cancer-predisposing syndrome, combined immunodeficiency due to dimerization defective IKAROS mutation, late-onset combined immunodeficiency due to ICOSL deficiency, combined immunodeficiency-hypogammaglobulinemia-skeletal anomalies syndrome due to IKBKA deficiency, early-onset combined immunodeficiency with low ig due to dominant negative IKAROS mutation, combined immunodeficiency with low Ig due to BCL10 deficiency, IRF4-related combined immunodeficiency, NFATC1-related combined immunodeficiency, POLD3-related combined immunodeficiency

Subtypes (3): MHC class I deficiency 1, MHC class I deficiency 2, MHC class I deficiency 3

Genetics & variants

GWAS landscape

No GWAS associations recorded — common-variant (GWAS) studies don’t cover this disease (typical for Mendelian / rare diseases). See the curated gene cohort and Mendelian overlap below.

Variant details and genetic-evidence tiers

ClinVar germline variants

600 retrieved; paginated sample, class counts are floors:

294 uncertain significance, 250 likely benign, 20 benign, 19 pathogenic, 8 benign/likely benign, 7 conflicting classifications of pathogenicity, 2 likely pathogenic

ClinVar	Variant (HGVS)	Gene	Classification	Review
2033577	NM_001290043.2(TAP2):c.724C>T (p.Gln242Ter)	LOC107648851	Pathogenic	criteria provided, single submitter
2136377	NM_001290043.2(TAP2):c.658C>T (p.Arg220Ter)	LOC107648851	Pathogenic	criteria provided, single submitter
1074323	NM_000593.6(TAP1):c.1866_1879del (p.His622fs)	TAP1	Pathogenic	criteria provided, single submitter
13732	NM_000593.6(TAP1):c.599-1G>A	TAP1	Pathogenic	no assertion criteria provided
1455001	NM_000593.6(TAP1):c.1005del (p.Pro336fs)	TAP1	Pathogenic	criteria provided, single submitter
2054486	NC_000006.12:g.32853728dup	TAP1	Pathogenic	criteria provided, single submitter
2096743	NM_000593.6(TAP1):c.335T>A (p.Leu112Ter)	TAP1	Pathogenic	criteria provided, single submitter
2419034	NM_000593.6(TAP1):c.934C>T (p.Arg312Ter)	TAP1	Pathogenic	criteria provided, single submitter
2572421	NM_000593.6(TAP1):c.884del (p.Leu295fs)	TAP1	Pathogenic	criteria provided, single submitter
2705098	NM_000593.6(TAP1):c.1217_1218del (p.Val406fs)	TAP1	Pathogenic	criteria provided, single submitter
13728	NM_001290043.2(TAP2):c.979del (p.Arg327fs)	TAP2	Pathogenic	no assertion criteria provided
1443971	NM_001290043.2(TAP2):c.1260del (p.Ser421fs)	TAP2	Pathogenic	criteria provided, single submitter
1452277	NM_001290043.2(TAP2):c.824del (p.Leu275fs)	TAP2	Pathogenic	criteria provided, single submitter
1456619	NM_001290043.2(TAP2):c.373del (p.Gln125fs)	TAP2	Pathogenic	criteria provided, single submitter
1459385	NM_001290043.2(TAP2):c.1101G>A (p.Trp367Ter)	TAP2	Pathogenic	criteria provided, single submitter
1928904	NM_001290043.2(TAP2):c.1837C>T (p.Gln613Ter)	TAP2	Pathogenic	criteria provided, single submitter
1996596	NM_001290043.2(TAP2):c.1606C>T (p.Gln536Ter)	TAP2	Pathogenic	criteria provided, single submitter
2075917	NM_001290043.2(TAP2):c.224del (p.Leu75fs)	TAP2	Pathogenic	criteria provided, single submitter
2164746	NM_001290043.2(TAP2):c.815del (p.Leu272fs)	TAP2	Pathogenic	criteria provided, single submitter
1480495	NM_001290043.2(TAP2):c.494-2A>G	LOC107648851	Likely pathogenic	criteria provided, single submitter
2501118	NM_001290043.2(TAP2):c.814_815delinsC (p.Leu272fs)	TAP2	Likely pathogenic	criteria provided, single submitter
1060163	NM_000593.6(TAP1):c.746A>G (p.Tyr249Cys)	TAP1	Conflicting classifications of pathogenicity	criteria provided, conflicting classifications
1339543	NM_000593.6(TAP1):c.1937G>A (p.Gly646Asp)	TAP1	Conflicting classifications of pathogenicity	criteria provided, conflicting classifications
1386307	NM_000593.6(TAP1):c.362C>T (p.Ala121Val)	TAP1	Conflicting classifications of pathogenicity	criteria provided, conflicting classifications
1032425	NM_001290043.2(TAP2):c.1345C>T (p.Arg449Ter)	TAP2	Conflicting classifications of pathogenicity	criteria provided, conflicting classifications
1470803	NM_001290043.2(TAP2):c.1742A>G (p.Gln581Arg)	TAP2	Conflicting classifications of pathogenicity	criteria provided, conflicting classifications
1906410	NM_001290043.2(TAP2):c.166A>G (p.Arg56Gly)	TAP2	Conflicting classifications of pathogenicity	criteria provided, conflicting classifications
2174842	NM_001290043.2(TAP2):c.1190A>G (p.Gln397Arg)	TAP2	Conflicting classifications of pathogenicity	criteria provided, conflicting classifications
1004055	NM_001290043.2(TAP2):c.524G>A (p.Arg175His)	LOC107648851	Uncertain significance	criteria provided, single submitter
1023763	NM_001290043.2(TAP2):c.515A>T (p.Tyr172Phe)	LOC107648851	Uncertain significance	criteria provided, single submitter

Genes & proteins

Mendelian disease overlap and somatic drivers

GenCC: 20 · Orphanet: 6 · OMIM-shared: 0 · Dual-evidence (GWAS+Mendelian): 0

GenCC gene–disease validity (cohort genes)

the Disease column is the GenCC-asserted condition — a cohort gene’s strongest validity may be for a related predisposition syndrome.

Gene	Classification	Inheritance	Disease	Records
TAP1	Definitive	Autosomal recessive	MHC class I deficiency	6
TAP2	Strong	Autosomal recessive	MHC class I deficiency	4
TAPBP	Moderate	Autosomal recessive	MHC class I deficiency 1	4
B2M	Supportive	Autosomal recessive	MHC class I deficiency	6

Orphanet rare-disease linkage (cohort genes)

Gene	Orphanet ID	Rare disease
TAPBP	Orphanet:34592	Immunodeficiency by defective expression of MHC class I
TAP1	Orphanet:34592	Immunodeficiency by defective expression of MHC class I
TAP2	Orphanet:34592	Immunodeficiency by defective expression of MHC class I
B2M	Orphanet:314652	Variant ABeta2M amyloidosis
B2M	Orphanet:34592	Immunodeficiency by defective expression of MHC class I
PSMB8	Orphanet:324977	Proteasome-associated autoinflammatory syndrome

Cohort genes → proteins

7 cohort genes, 6 distinct canonical proteins.

Evidence partition

Subset	Genes
multi_evidence	7

Cohort genes (full)

Symbol	HGNC	Ensembl	UniProt	Name	Evidence
TAPBP	HGNC:11566	ENSG00000231925	O15533	Tapasin	gencc,clinvar
TAP1	HGNC:43	ENSG00000168394	Q03518	Antigen peptide transporter 1	gencc,clinvar
TAP2	HGNC:44	ENSG00000204267	Q03519	Antigen peptide transporter 2	gencc,clinvar
B2M	HGNC:914	ENSG00000166710	P61769	Beta-2-microglobulin	gencc
PSMB8-AS1	HGNC:39758	ENSG00000204261		PSMB8 antisense RNA 1	clinvar
B3GALT4	HGNC:919	ENSG00000235863	O96024	Beta-1,3-galactosyltransferase 4	clinvar
PSMB8	HGNC:9545	ENSG00000204264	P28062	Proteasome subunit beta type-8	clinvar

Cohort function summary

Lead sentence per gene, UniProt-curated.

Symbol	Protein name	Function (lead sentence)
TAPBP	Tapasin	Involved in the association of MHC class I with transporter associated with antigen processing (TAP) and in the assembly of MHC class I with peptide (peptide loading).
TAP1	Antigen peptide transporter 1	ABC transporter associated with antigen processing.
TAP2	Antigen peptide transporter 2	ABC transporter associated with antigen processing.
B2M	Beta-2-microglobulin	Component of the class I major histocompatibility complex (MHC).
B3GALT4	Beta-1,3-galactosyltransferase 4	Involved in GM1/GD1B/GA1 ganglioside biosynthesis.
PSMB8	Proteasome subunit beta type-8	The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH.

Protein-family classification

Druggable: 5 · Difficult: 0 · Unknown: 2 · Druggable fraction: 0.71

Family distribution

Cohort families vs a genome-wide background (hypergeometric, BH-FDR; fold = observed/expected). Counts kept; sorted by enrichment, so the catch-all Other/Unknown bucket no longer leads.

Family	Genes	Fold	FDR
Transporter	2	22.2×	0.013
Antibody/Immunoglobulin	2	8.3×	0.044
Enzyme (other)	1	1.7×	0.609
Other/Unknown	2	0.5×	0.968

Per-gene assignment

Symbol	Family	Druggable?	EC	InterPro (top 3)
TAPBP	Antibody/Immunoglobulin	yes		Ig_C1-set, Ig-like_dom, Tapasin
TAP1	Transporter	yes	7.4.2.14	ABC_transporter-like_ATP-bd, AAA+_ATPase, ABC1_TM_dom
TAP2	Transporter	yes	7.4.2.14	ABC_transporter-like_ATP-bd, AAA+_ATPase, Tap2/ABCB3
B2M	Antibody/Immunoglobulin	yes		Ig/MHC_CS, Ig_C1-set, Ig-like_dom
PSMB8-AS1	Other/Unknown	no
B3GALT4	Enzyme (other)	yes	2.4.1.62	Glyco_trans_31
PSMB8	Other/Unknown	no		Pept_T1A_subB, Proteasome_sua/b, Proteasome_bsu_CS

Expression context

Cohort genes with no expression data: 0.

5 cohort genes are a single-cell marker in ≥1 SCXA experiment.

Breadth distribution (Bgee present_calls)

Bucket	Genes
narrow (1-5 tissues)	0
moderate (6-20)	0
broad (>20)	7
unknown	0

Top tissues across cohort

Tissue	Cohort genes
granulocyte	6
monocyte	3
leukocyte	3
lymph node	2
vermiform appendix	2
blood	1
bone marrow cell	1
lower esophagus mucosa	1
mucosa of transverse colon	1
spleen	1

Per-gene tissue summary (top 30)

Symbol	Bgee breadth	FANTOM5 breadth	SCXA	Top tissues
TAPBP	133	ubiquitous	marker	bone marrow cell, granulocyte, blood
TAP1	134	ubiquitous	marker	granulocyte, vermiform appendix, lymph node
TAP2	134	ubiquitous	yes	vermiform appendix, lymph node, monocyte
B2M	134	ubiquitous	marker	granulocyte, monocyte, leukocyte
PSMB8-AS1	132	ubiquitous	marker	granulocyte, leukocyte, monocyte
B3GALT4	170	ubiquitous	yes	lower esophagus mucosa, mucosa of transverse colon, granulocyte
PSMB8	132	ubiquitous	marker	granulocyte, leukocyte, spleen

Protein interactions among cohort

Intra-cohort edges: 7.

Hub genes (top 10 by interactor count)

Symbol	Interactor count
PSMB8	3,188
TAPBP	2,253
TAP1	2,139
TAP2	1,507
B3GALT4	831
B2M	415
PSMB8-AS1	0

Intra-cohort edges

A	B	Sources
B2M	TAP2	intact
PSMB8	TAP1	intact, string_interaction
PSMB8	TAP2	intact, string_interaction
PSMB8	TAPBP	string_interaction
TAP1	TAP2	biogrid_interaction, intact, string_interaction
TAP1	TAPBP	biogrid_interaction, intact, string_interaction
TAP2	TAPBP	biogrid_interaction, intact, string_interaction

Structural data

PDB: 5 · AlphaFold-only: 1 · No structure: 1

Cohort genes with PDB structures (top 30)

Symbol	UniProt	PDB entries
B2M	P61769	1,226
TAP1	Q03518	22
PSMB8	P28062	22
TAP2	Q03519	21
TAPBP	O15533	8

AlphaFold-only cohort genes (top 30 by pLDDT)

Symbol	UniProt	pLDDT
B3GALT4	O96024	84.89

Function

Pathway analysis

Distinct Reactome pathways touched by cohort: 44. Enrichment computed across 7 evidence-associated genes (6 with Reactome annotation).

Pathways by enrichment

Over-representation of cohort genes vs the genome-wide background (hypergeometric test, Benjamini-Hochberg FDR; fold = observed/expected over 6 annotated cohort genes). Counts and members are kept as ground-truth; sorted by enrichment.

Pathway	Cohort genes	Fold	FDR	Sample cohort genes
ER-Phagosome pathway	5	108.1×	6e-09	TAPBP, TAP1, TAP2, B2M, PSMB8
Antigen Presentation: Folding, assembly and peptide loading of class I MHC	4	262.5×	1e-08	TAPBP, TAP1, TAP2, B2M
Antigen processing-Cross presentation	3	158.6×	8e-06	TAP1, TAP2, B2M
Class I MHC mediated antigen processing & presentation	3	35.0×	6e-04	TAP1, TAP2, B2M
Adaptive Immune System	3	14.9×	0.006	TAP1, TAP2, B2M
Modulation by Mtb of host immune system	1	271.9×	0.025	B2M
Nef mediated downregulation of MHC class I complex cell surface expression	1	190.3×	0.025	B2M
Blood group systems biosynthesis	1	190.3×	0.025	B3GALT4
Infection with Mycobacterium tuberculosis	1	190.3×	0.025	B2M
Endosomal/Vacuolar pathway	1	173.0×	0.025	B2M
Lewis blood group biosynthesis	1	112.0×	0.029	B3GALT4
Nef-mediates down modulation of cell surface receptors by recruiting them to clathrin adapters	1	105.7×	0.029	B2M
The role of Nef in HIV-1 replication and disease pathogenesis	1	105.7×	0.029	B2M
Glycosphingolipid biosynthesis	1	100.2×	0.029	B3GALT4
Antigen processing: Ub, ATP-independent proteasomal degradation	1	95.2×	0.029	PSMB8
Immune System	3	6.5×	0.029	TAP1, TAP2, B2M
DAP12 interactions	1	79.3×	0.032	B2M
DAP12 signaling	1	61.4×	0.039	B2M
Host Interactions of HIV factors	1	56.0×	0.039	B2M
Bacterial Infection Pathways	1	56.0×	0.039	B2M
Glycosphingolipid metabolism	1	50.1×	0.041	B3GALT4
Cross-presentation of soluble exogenous antigens (endosomes)	1	42.3×	0.047	PSMB8
Proteasome assembly	1	34.0×	0.056	PSMB8
Sphingolipid metabolism	1	28.0×	0.065	B3GALT4
Interferon alpha/beta signaling	1	25.4×	0.068	PSMB8
Interferon gamma signaling	1	20.9×	0.072	B2M
Metabolism of carbohydrates and carbohydrate derivatives	1	20.0×	0.072	B3GALT4
Interferon Signaling	1	20.0×	0.072	B2M
HIV Infection	1	19.8×	0.072	B2M
SARS-CoV-2-host interactions	1	19.8×	0.072	B2M

GO biological processes by enrichment

Over-representation of cohort genes vs the genome-wide background (hypergeometric test, Benjamini-Hochberg FDR; fold = observed/expected over 6 annotated cohort genes). Counts and members are kept as ground-truth; sorted by enrichment.

GO term	Cohort genes	Fold	FDR	Sample cohort genes
antigen processing and presentation of endogenous peptide antigen via MHC class I	4	1404.3×	2e-11	TAPBP, TAP1, TAP2, B2M
antigen processing and presentation of exogenous protein antigen via MHC class Ib, TAP-dependent	2	2808.7×	2e-06	TAP2, B2M
cytosol to endoplasmic reticulum transport	2	2808.7×	2e-06	TAP1, TAP2
peptide antigen assembly with MHC class I protein complex	2	936.2×	2e-05	TAPBP, B2M
response to molecule of bacterial origin	2	702.2×	3e-05	TAP2, B2M
T cell mediated cytotoxicity	2	374.5×	1e-04	TAP2, B2M
positive regulation of T cell mediated cytotoxicity	2	170.2×	4e-04	TAP2, B2M
MHC class Ib protein complex assembly	1	2808.7×	0.002	TAPBP
antigen processing and presentation of endogenous peptide antigen via MHC class Ib via ER pathway, TAP-dependent	1	2808.7×	0.002	TAP2
negative regulation of iron ion transport	1	2808.7×	0.002	B2M
peptide antigen stabilization	1	2808.7×	0.002	TAPBP
transmembrane transport	2	56.2×	0.002	TAP1, TAP2
antigen processing and presentation of endogenous peptide antigen via MHC class I via ER pathway, TAP-dependent	1	1404.3×	0.002	TAP2
regulation of iron ion transport	1	1404.3×	0.002	B2M
cellular response to iron(III) ion	1	1404.3×	0.002	B2M
negative regulation of forebrain neuron differentiation	1	1404.3×	0.002	B2M
peptide antigen transport	1	936.2×	0.004	TAP2
antigen processing and presentation of exogenous peptide antigen via MHC class I, TAP-dependent	1	702.2×	0.004	TAPBP
peptide transport	1	702.2×	0.004	TAP1
regulation of erythrocyte differentiation	1	468.1×	0.006	B2M
cellular response to iron ion	1	401.2×	0.007	B2M
cellular response to nicotine	1	351.1×	0.007	B2M
negative regulation of receptor-mediated endocytosis	1	312.1×	0.008	B2M
transferrin transport	1	255.3×	0.009	B2M
positive regulation of T cell cytokine production	1	216.1×	0.010	B2M
positive regulation of cellular senescence	1	216.1×	0.010	B2M
ganglioside biosynthetic process	1	187.2×	0.011	B3GALT4
peptide antigen assembly with MHC class II protein complex	1	175.5×	0.011	B2M
regulation of protein complex stability	1	175.5×	0.011	TAPBP
positive regulation of receptor-mediated endocytosis	1	133.8×	0.013	B2M

Therapeutics

Drug target analysis

Approved (phase 4): 1 · Phase ≥3: 1 · Phased (≥1): 1 · Undrugged: 6

Druggability breadth: 4 of 7 evidence-associated genes (57%) have a ChEMBL target (buckets above are over the deeply-mined display cohort).

Genes with an approved drug

The molecule shown is one approved compound that hits the gene — not necessarily a drug of choice or one indicated for this disease.

Symbol	Example approved molecule
PSMB8	BORTEZOMIB

Top cohort targets by molecule count

Symbol	Molecules	Max phase
PSMB8	7	4
TAPBP	0	0
TAP1	0	0
TAP2	0	0
B2M	0	0
PSMB8-AS1	0	0
B3GALT4	0	0

Drugs targeting cohort genes (top 30)

Molecule	Max phase	Targets in cohort
BORTEZOMIB	4	PSMB8
CARFILZOMIB	4	PSMB8
IXAZOMIB	3	PSMB8
MARIZOMIB	3	PSMB8
OPROZOMIB	2	PSMB8
DELANZOMIB	2	PSMB8
ZETOMIPZOMIB	2	PSMB8

Bioactivity and enzyme data

Enzyme cohort genes (≥1 EC): 3.

Cohort genes with ChEMBL bioactivity (full, sorted by assay count)

Symbol	Assays	Type breakdown
PSMB8	262	Binding:250, ADMET:9, Functional:3
B2M	5	Binding:5
TAP1	4	Binding:4
TAP2	3	Binding:3

Cohort enzymes (BRENDA EC)

Symbol	EC numbers	Names
TAP1	7.4.2.14, 7.4.2.5	ABC-type antigen peptide transporter, bacterial ABC-type protein transporter
TAP2	7.4.2.14, 7.4.2.5	ABC-type antigen peptide transporter, bacterial ABC-type protein transporter
B3GALT4	2.4.1.62	ganglioside galactosyltransferase

Cohort genes with high screening signal

≥100 ChEMBL assays — a studied-ness signal; see Therapeutics for approved-drug status.

Symbol	ChEMBL assays
PSMB8	262

Pharmacogenomics

Cohort genes with a PharmGKB record: 6; with CPIC/DPWG dosing guidelines: 0.

No cohort gene has a CPIC/DPWG genotype-guided dosing guideline (PharmGKB).

Chemical tractability of cohort targets

7 approved/phased compounds have measured bioactivity against a cohort gene (and aren’t yet in disease-level trials). This is a research / tractability signal, NOT a therapeutic recommendation — a bioactivity row often reflects off-target or screening binding (e.g. promiscuous kinase inhibitors against a cohort kinase), implying no disease mechanism.

Compound	Max phase	Cohort target (bioactivity)
BORTEZOMIB	4	PSMB8
CARFILZOMIB	4	PSMB8
IXAZOMIB	3	PSMB8
MARIZOMIB	3	PSMB8
OPROZOMIB	2	PSMB8
DELANZOMIB	2	PSMB8
ZETOMIPZOMIB	2	PSMB8

Druggability pyramid

Cohort genes binned by druggability tier (high → low):

Tier	Definition	Genes	Symbols
A	Approved (phase 4 drug)	1	PSMB8
B	Phased (≥1) drug, not yet approved	0
C	Druggable family + PDB, no drug	4	TAPBP, TAP1, TAP2, B2M
D	Druggable family + AlphaFold only, no drug	1	B3GALT4
E	Difficult family or no structure, no drug	1	PSMB8-AS1

Undrugged target profiles

6 cohort genes are undrugged. Ranked by ‘starting-point quality’ (assay depth + drugged-partner adjacency).

Symbol	ChEMBL assays	Drugged partners (top 3)
TAP1	4	PSMB8
TAP2	3	PSMB8
TAPBP	0	—
B2M	5	—
PSMB8-AS1	0	—
B3GALT4	0	—

Clinical trials & evidence

Clinical trials

Clinical trials: 0.