H2AC25

gene
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Also known as MGC3165

Summary

H2AC25 (H2A clustered histone 25, HGNC:20507) is a protein-coding gene on chromosome 1q42.13, encoding Histone H2A type 3 (Q7L7L0). Core component of nucleosome.

Histones are basic nuclear proteins that are responsible for the nucleosome structure of the chromosomal fiber in eukaryotes. Nucleosomes consist of approximately 146 bp of DNA wrapped around a histone octamer composed of pairs of each of the four core histones (H2A, H2B, H3, and H4). The chromatin fiber is further compacted through the interaction of a linker histone, H1, with the DNA between the nucleosomes to form higher order chromatin structures. This gene is intronless and encodes a replication-dependent histone that is a member of the histone H2A family. Transcripts from this gene contain a palindromic termination element.

Source: NCBI Gene 92815 — RefSeq curated summary.

At a glance

  • GWAS associations: 2
  • Clinical variants (ClinVar): 29 total
  • MANE Select transcript: NM_033445

Identifiers

Gene identifiers

FieldValue
HGNC IDHGNC:20507
Approved symbolH2AC25
NameH2A clustered histone 25
Location1q42.13
Locus typegene with protein product
StatusApproved
AliasesMGC3165
Ensembl geneENSG00000181218
Ensembl biotypeprotein_coding
OMIM615015
Entrez92815

Gene structure

Transcript identifiers

Ensembl transcripts: 3 — 2 protein_coding, 1 nonsense_mediated_decay

ENST00000366695, ENST00000689584, ENST00000691624

RefSeq mRNA: 1 — MANE Select: NM_033445 NM_033445

CCDS: CCDS1573

Canonical transcript exons

ENST00000645741 — 0 exons

Expression profiles

Bgee: expression breadth ubiquitous, 132 present calls, max score 94.17.

FANTOM5 (CAGE): breadth ubiquitous, TPM avg 78.9401 / max 2437.4950, expressed in 1719 samples.

FANTOM5 promoters (1 alternative TSS)

Promoter IDTPM avgSamples expressed
1784278.94011719

Top tissues by expression

133 total, by Bgee expression score (0-100, higher = more expressed):

TissueAnatomy IDExpression scoreQuality
cerebellar hemisphereUBERON:000224594.17gold quality
cerebellumUBERON:000203794.16gold quality
cerebellar cortexUBERON:000212994.15gold quality
right hemisphere of cerebellumUBERON:001489093.81gold quality
male germ line stem cell (sensu Vertebrata) in testisCL:0000089 ∩ UBERON:000047392.27gold quality
ganglionic eminenceUBERON:000402391.75gold quality
cortical plateUBERON:000534391.53gold quality
left adrenal gland cortexUBERON:003582590.19gold quality
apex of heartUBERON:000209889.81gold quality
left adrenal glandUBERON:000123489.52gold quality
right adrenal glandUBERON:000123389.23gold quality
right adrenal gland cortexUBERON:003582789.16gold quality
primordial germ cell in gonadCL:0000670 ∩ UBERON:000099187.57gold quality
adrenal glandUBERON:000236986.29gold quality
ventricular zoneUBERON:000305385.96gold quality
nucleus accumbensUBERON:000188285.15gold quality
prefrontal cortexUBERON:000045184.79gold quality
putamenUBERON:000187484.07gold quality
brainUBERON:000095583.90gold quality
frontal cortexUBERON:000187083.64gold quality
heart left ventricleUBERON:000208483.53gold quality
Brodmann (1909) area 9UBERON:001354083.45gold quality
caudate nucleusUBERON:000187383.23gold quality
cerebral cortexUBERON:000095683.06gold quality
vaginaUBERON:000099682.94gold quality
dorsolateral prefrontal cortexUBERON:000983482.78gold quality
right frontal lobeUBERON:000281082.71gold quality
olfactory segment of nasal mucosaUBERON:000538682.49gold quality
skin of abdomenUBERON:000141682.36gold quality
Ammon’s hornUBERON:000195482.36gold quality

Single-cell (SCXA)

Detected in 3 experiment(s), a significant marker in 2.

ExperimentMarker?Max mean expression
E-MTAB-6505yes22578.60
E-MTAB-5061yes6.05
E-ANND-3no0.39

Regulation

Is transcription factor: no

Literature-anchored findings (GeneRIF, showing 2)

  • Overexpression of HIST3H2A reversed the anti-proliferation effects induced by miR-516a-5p in non-small cell lung cancer cells. (PMID:30966836)
  • HIST3H2A promotes the progression of prostate cancer through inhibiting cell necroptosis. (PMID:38684944)

Cross-species orthologs

22 orthologs

OrganismSymbolGene ID
mus_musculusH2ac25ENSMUSG00000078851
rattus_norvegicusH2ac25ENSRNOG00000064520
drosophila_melanogasterHis2A:CG31618FBGN0051618
drosophila_melanogasterHis2A:CG33808FBGN0053808
drosophila_melanogasterHis2A:CG33814FBGN0053814
drosophila_melanogasterHis2A:CG33817FBGN0053817
drosophila_melanogasterHis2A:CG33820FBGN0053820
drosophila_melanogasterHis2A:CG33823FBGN0053823
drosophila_melanogasterHis2A:CG33826FBGN0053826
drosophila_melanogasterHis2A:CG33829FBGN0053829
drosophila_melanogasterHis2A:CG33832FBGN0053832
drosophila_melanogasterHis2A:CG33835FBGN0053835
drosophila_melanogasterHis2A:CG33838FBGN0053838
drosophila_melanogasterHis2A:CG33841FBGN0053841
drosophila_melanogasterHis2A:CG33844FBGN0053844
drosophila_melanogasterHis2A:CG33847FBGN0053847
drosophila_melanogasterHis2A:CG33850FBGN0053850
drosophila_melanogasterHis2A:CG33853FBGN0053853
drosophila_melanogasterHis2A:CG33856FBGN0053856
drosophila_melanogasterHis2A:CG33859FBGN0053859
drosophila_melanogasterHis2A:CG33862FBGN0053862
drosophila_melanogasterHis2A:CG33865FBGN0053865

Paralogs (27): MACROH2A2 (ENSG00000099284), H2AZ2 (ENSG00000105968), MACROH2A1 (ENSG00000113648), H2AZ1 (ENSG00000164032), H2AC1 (ENSG00000164508), H2AC6 (ENSG00000180573), H2AC20 (ENSG00000184260), H2AC21 (ENSG00000184270), H2AX (ENSG00000188486), H2AC13 (ENSG00000196747), H2AC11 (ENSG00000196787), H2AC7 (ENSG00000196866), H2AL3 (ENSG00000229674), H2AJ (ENSG00000246705), H2AL1Q (ENSG00000249467), H2AB1 (ENSG00000274183), H2AC12 (ENSG00000274997), H2AC15 (ENSG00000275221), H2AC14 (ENSG00000276368), H2AC16 (ENSG00000276903), H2AC8 (ENSG00000277075), H2AB3 (ENSG00000277745), H2AB2 (ENSG00000277858), H2AC4 (ENSG00000278463), H2AC17 (ENSG00000278677), H2AC18 (ENSG00000288825), H2AC19 (ENSG00000288859)

Protein

Protein identifiers

Histone H2A type 3Q7L7L0 (reviewed: Q7L7L0)

Alternative names: H2A-clustered histone 25

All UniProt accessions (1): Q7L7L0

UniProt curated annotations — full annotation on UniProt →

Function. Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling.

Subunit / interactions. The nucleosome is a histone octamer containing two molecules each of H2A, H2B, H3 and H4 assembled in one H3-H4 heterotetramer and two H2A-H2B heterodimers. The octamer wraps approximately 147 bp of DNA.

Subcellular location. Nucleus. Chromosome.

Post-translational modifications. Deiminated on Arg-4 in granulocytes upon calcium entry. Monoubiquitination of Lys-120 (H2AK119Ub) by RING1, TRIM37 and RNF2/RING2 complex gives a specific tag for epigenetic transcriptional repression and participates in X chromosome inactivation of female mammals. It is involved in the initiation of both imprinted and random X inactivation. Ubiquitinated H2A is enriched in inactive X chromosome chromatin. Ubiquitination of H2A functions downstream of methylation of ‘Lys-27’ of histone H3 (H3K27me). H2AK119Ub by RNF2/RING2 can also be induced by ultraviolet and may be involved in DNA repair. Monoubiquitination of Lys-120 (H2AK119Ub) by TRIM37 may promote transformation of cells in a number of breast cancers. Following DNA double-strand breaks (DSBs), it is ubiquitinated through ‘Lys-63’ linkage of ubiquitin moieties by the E2 ligase UBE2N and the E3 ligases RNF8 and RNF168, leading to the recruitment of repair proteins to sites of DNA damage. Ubiquitination at Lys-14 and Lys-16 (H2AK13Ub and H2AK15Ub, respectively) in response to DNA damage is initiated by RNF168 that mediates monoubiquitination at these 2 sites, and ‘Lys-63’-linked ubiquitin are then conjugated to monoubiquitin; RNF8 is able to extend ‘Lys-63’-linked ubiquitin chains in vitro. Deubiquitinated by USP51 at Lys-14 and Lys-16 (H2AK13Ub and H2AK15Ub, respectively) after damaged DNA is repaired. H2AK119Ub and ionizing radiation-induced ‘Lys-63’-linked ubiquitination (H2AK13Ub and H2AK15Ub) are distinct events. Phosphorylation on Ser-2 (H2AS1ph) is enhanced during mitosis. Phosphorylation on Ser-2 by RPS6KA5/MSK1 directly represses transcription. Acetylation of H3 inhibits Ser-2 phosphorylation by RPS6KA5/MSK1. Phosphorylation at Thr-121 (H2AT120ph) by DCAF1 is present in the regulatory region of many tumor suppresor genes and down-regulates their transcription. Glutamine methylation at Gln-105 (H2AQ104me) by FBL is specifically dedicated to polymerase I. It is present at 35S ribosomal DNA locus and impairs binding of the FACT complex. Symmetric dimethylation on Arg-4 by the PRDM1/PRMT5 complex may play a crucial role in the germ-cell lineage. Crotonylation (Kcr) is specifically present in male germ cells and marks testis-specific genes in post-meiotic cells, including X-linked genes that escape sex chromosome inactivation in haploid cells. Crotonylation marks active promoters and enhancers and confers resistance to transcriptional repressors. It is also associated with post-meiotically activated genes on autosomes. Lactylated in macrophages by EP300/P300 by using lactoyl-CoA directly derived from endogenous or exogenous lactate, leading to stimulates gene transcription.

Similarity. Belongs to the histone H2A family.

RefSeq proteins (1): NP_254280* (*=MANE)

Domains & families (InterPro)

IDNameType
IPR002119Histone_H2AFamily
IPR007125H2A/H2B/H3Domain
IPR009072Histone-foldHomologous_superfamily
IPR032454Histone_H2A_CDomain
IPR032458Histone_H2A_CSConserved_site

Pfam: PF00125, PF16211

UniProt features (53 total): modified residue 35, helix 5, cross-link 3, strand 3, turn 2, initiator methionine 1, chain 1, region of interest 1, compositionally biased region 1, mutagenesis site 1

Structure

Experimental structures (PDB)

2 structures.

PDBMethodResolution (Å)
9ECPELECTRON MICROSCOPY1.91
9FH9ELECTRON MICROSCOPY2.5

Predicted structure (AlphaFold)

ModelpLDDTFraction very-high
AF-Q7L7L0-F191.200.80

Functional residue map

Curated UniProt residues grouped by drug-discovery relevance — catalytic, ligand-binding, modification, and mutation-validated positions. Source: UniProtKB sequence features.

Post-translational modifications (38): 10, 10, 10, 10, 14, 14, 16, 37, 37, 37, 37, 75, 76, 96, 96, 96, 96, 96, 105, 119 …

Mutagenesis-validated functional residues (1):

PositionPhenotype
2blocks the inhibition of transcription by rps6ka5/msk1.

Function

Pathways and Gene Ontology

Reactome pathways

9 pathways

IDPathway
R-HSA-3214815HDACs deacetylate histones
R-HSA-3214847HATs acetylate histones
R-HSA-3214858RMTs methylate histone arginines
R-HSA-5689603UCH proteinases
R-HSA-5689880Ub-specific processing proteases
R-HSA-5689901Metalloprotease DUBs
R-HSA-9609690HCMV Early Events
R-HSA-9610379HCMV Late Events
R-HSA-9918481Dengue Virus-Host Interactions

MSigDB gene sets: 217 (showing top): RODRIGUES_THYROID_CARCINOMA_POORLY_DIFFERENTIATED_UP, CCAWYNNGAAR_UNKNOWN, GOBP_CELLULAR_RESPONSE_TO_UV, FISCHER_G1_S_CELL_CYCLE, GOBP_CELLULAR_RESPONSE_TO_LIGHT_STIMULUS, STARK_PREFRONTAL_CORTEX_22Q11_DELETION_DN, GRAESSMANN_APOPTOSIS_BY_DOXORUBICIN_UP, GRAESSMANN_RESPONSE_TO_MC_AND_DOXORUBICIN_UP, GOBP_NEGATIVE_REGULATION_OF_GENE_EXPRESSION_EPIGENETIC, KINSEY_TARGETS_OF_EWSR1_FLII_FUSION_DN, GOBP_RESPONSE_TO_UV, GOBP_DNA_DAMAGE_RESPONSE, GOBP_RESPONSE_TO_RADIATION, HELLER_HDAC_TARGETS_SILENCED_BY_METHYLATION_UP, GOBP_RESPONSE_TO_ABIOTIC_STIMULUS

GO Biological Process (3): nucleosome disassembly (GO:0006337), heterochromatin formation (GO:0031507), UV-damage excision repair (GO:0070914)

GO Molecular Function (4): DNA binding (GO:0003677), structural constituent of chromatin (GO:0030527), protein heterodimerization activity (GO:0046982), protein binding (GO:0005515)

GO Cellular Component (4): nucleosome (GO:0000786), nucleus (GO:0005634), extracellular exosome (GO:0070062), chromosome (GO:0005694)

Reactome top-level categories

Rollup of top-4 pathways:

CategoryPathways
Chromatin modifying enzymes3
Deubiquitination3
HCMV Infection2
Dengue Virus Infection1

GO top-level categories

Rollup of top GO terms by namespace:

CategoryTerms
chromatin2
protein-DNA complex disassembly1
nucleosome organization1
cellular component assembly1
heterochromatin boundary formation1
negative regulation of gene expression, epigenetic1
heterochromatin organization1
DNA repair1
cellular response to UV1
nucleic acid binding1
structural molecule activity1
protein dimerization activity1
binding1
protein-DNA complex1
intracellular membrane-bounded organelle1
extracellular vesicle1
intracellular membraneless organelle1

Protein interactions and networks

STRING

1192 interactions, top by confidence (×1000):

Protein AProtein BPartner UniProtScore
H2AC25H1-1Q02539731
H2AC25H2BC21Q16778550
H2AC25H2BC26Q8N257509
H2AC25H3C1P02295497
H2AC25H1-4P10412458
H2AC25H1-5P16401444
H2AC25PCDHB4Q9Y5E5433
H2AC25H2BC1Q96A08431
H2AC25PCDHB7Q9Y5E2426
H2AC25PCDHB3Q9Y5E6425
H2AC25CDK5R2Q13319418
H2AC25EEF1A1P04719401
H2AC25PCDHB10Q9UN67392
H2AC25NRARPQ7Z6K4384
H2AC25DHTKD1Q96HY7380

IntAct

51 interactions, top by confidence:

ABTypeScore
OPG044DDX3Xpsi-mi:“MI:0914”(association)0.730
H2AC25psi-mi:“MI:0407”(direct interaction)0.620
H2AC25psi-mi:“MI:0407”(direct interaction)0.620
H2AC25psi-mi:“MI:0915”(physical association)0.560
H2AC25psi-mi:“MI:0915”(physical association)0.560
HSF2BPH2AC25psi-mi:“MI:0915”(physical association)0.560
H2AC25NDUFV2psi-mi:“MI:0915”(physical association)0.560
P/V/CKPNA3psi-mi:“MI:0914”(association)0.530
UBE2BH2AC25psi-mi:“MI:0407”(direct interaction)0.520
NOP1H2AC25psi-mi:“MI:0213”(methylation reaction)0.440
RNF168H2AC25psi-mi:“MI:0407”(direct interaction)0.440
SPT16H2AC25psi-mi:“MI:0915”(physical association)0.400
ORF73ECI2psi-mi:“MI:0914”(association)0.350
CHD1LH2BC12psi-mi:“MI:0914”(association)0.350
UBE2BUbr2psi-mi:“MI:0914”(association)0.350
H2AC25SSRP1psi-mi:“MI:0914”(association)0.350
NEK4E2F8psi-mi:“MI:0914”(association)0.350
RALBP1HMGB1P1psi-mi:“MI:0914”(association)0.350
PRKCBHNRNPDLpsi-mi:“MI:0914”(association)0.350
MYLK2psi-mi:“MI:0914”(association)0.350
ELK4MYO1Cpsi-mi:“MI:0914”(association)0.350
RPS6KA3BAG2psi-mi:“MI:0914”(association)0.350
PRKCBCHEK1psi-mi:“MI:0914”(association)0.350
CAMK2ASEC16Apsi-mi:“MI:0914”(association)0.350
Ppsi-mi:“MI:0914”(association)0.350

BioGRID (157): KRTAP10-3 (Two-hybrid), HIST3H2A (Affinity Capture-MS), HIST3H2A (Two-hybrid), HIST3H2A (Affinity Capture-MS), HIST3H2A (Affinity Capture-MS), HIST3H2A (Affinity Capture-MS), HIST3H2A (Affinity Capture-MS), HIST3H2A (Affinity Capture-MS), HIST3H2A (Affinity Capture-MS), HIST3H2A (Affinity Capture-MS), HIST3H2A (Affinity Capture-RNA), HIST3H2A (Reconstituted Complex), HIST3H2A (Affinity Capture-MS), HIST3H2A (Affinity Capture-MS), HIST3H2A (Two-hybrid)

ESM2 similar proteins: A1A4R1, A9UMV8, C0HKE1, C0HKE2, C0HKE3, C0HKE4, C0HKE5, C0HKE6, C0HKE7, C0HKE8, C0HKE9, P02262, P02263, P02270, P04908, P06897, P0C0S8, P0C0S9, P0C169, P0C170, P0CC09, P13912, P19178, P20671, P21896, P27325, P35061, P35062, P70082, P84052, Q07135, Q16777, Q3ZBX9, Q4FZT6, Q4R3X5, Q64522, Q64523, Q64598, Q6FI13, Q6GSS7

Diamond homologs: A0A097I1R9, A0A097I2B5, A0A0D2UG83, A1A4R1, A1CJ10, A1D8G8, A3LXE7, A3LZZ0, A5DBG4, A5DJJ2, A5DWF1, A5DXC6, A9UMV8, C0HKE1, C0HKE2, C0HKE3, C0HKE4, C0HKE5, C0HKE6, C0HKE7, C0HKE8, C0HKE9, L7HZV6, O74268, P02262, P02263, P02264, P04908, P04909, P04910, P04911, P04912, P06897, P07793, P08844, P0C0S8, P0C0S9, P0C169, P0C170, P0C952

SIGNOR signaling

3 interactions.

AEffectBMechanism
SLBP“up-regulates quantity by expression”H2AW“translation regulation”
DZIP3“up-regulates activity”H2AWmonoubiquitination
RPS6KA5“up-regulates activity”H2AWphosphorylation

Disease & clinical

Clinical variants and AI predictions

ClinVar

29 variants total. Per-class counts are floors (≥ shown; pagination cap):

ClassificationCount (floor)
Pathogenic0
Likely pathogenic0
Uncertain significance28
Likely benign1
Benign0

Top pathogenic / likely-pathogenic (0)

SpliceAI

125 predictions. Top by Δscore:

VariantEffectΔscore
1:228457648:TCGAG:Tdonor_gain0.6200
1:228457649:CGAGC:Cdonor_gain0.6200
1:228457774:G:Cdonor_gain0.5600
1:228457773:AG:Adonor_gain0.5500
1:228457431:G:Adonor_gain0.5400
1:228457430:TGCCC:Tdonor_gain0.4900
1:228457431:GCCCT:Gdonor_gain0.4700
1:228457432:CCCTT:Cdonor_gain0.4500
1:228457185:C:Adonor_gain0.4400
1:228457167:C:CTdonor_gain0.4300
1:228457166:C:CTdonor_gain0.4200
1:228457212:A:Gdonor_gain0.4100
1:228457213:C:Tdonor_gain0.4100
1:228457427:A:ACdonor_gain0.4100
1:228457428:C:CCdonor_gain0.4100
1:228457214:C:Tdonor_gain0.4000
1:228457432:C:CAdonor_gain0.4000
1:228457474:ACGG:Adonor_gain0.4000
1:228457475:CGGC:Cdonor_gain0.4000
1:228457592:T:TAdonor_gain0.4000
1:228457453:T:Adonor_gain0.3900
1:228457429:TTGCC:Tdonor_gain0.3800
1:228457209:C:Tdonor_gain0.3700
1:228457211:CACCT:Cdonor_gain0.3700
1:228457194:TAACA:Tdonor_gain0.3600
1:228457208:GCCCA:Gdonor_gain0.3600
1:228457209:CCCA:Cdonor_loss0.3600
1:228457210:CCAC:Cdonor_loss0.3600
1:228457210:CCACC:Cdonor_gain0.3600
1:228457211:CAC:Cdonor_loss0.3600

AlphaMissense

0 scored. Top likely-pathogenic:

dbSNP variants (sampled 300 via entrez): RS1000238442 (1:228458768 T>A,C), RS1001050817 (1:228458095 C>A,G,T), RS1002053230 (1:228457187 CTGT>C), RS1002084351 (1:228457042 G>T), RS1003133451 (1:228457383 C>A,G,T), RS1003578151 (1:228459643 G>A), RS1003611386 (1:228459394 C>T), RS1003893672 (1:228457092 T>C,G), RS1003987150 (1:228456898 T>C), RS1005427562 (1:228458307 A>G), RS1006021664 (1:228459412 C>T), RS1006164175 (1:228459062 C>G,T), RS1006483586 (1:228459274 C>G,T), RS1007247054 (1:228458986 C>A,T), RS1007334703 (1:228458782 C>T)

Disease associations

OMIM: gene MIM:615015 | disease phenotypes:

GenCC curated gene-disease

Mondo (0):

Orphanet (0):

HPO phenotypes

0 total (0 of 0 shown, HPO-id order):

GWAS associations

2 associations (top):

StudyTraitp-value
GCST003833_18Adult asthma7.000000e-08
GCST003833_2Adult asthma1.000000e-07

Drugs & pharmacology

Drug and pharmacology data

Is drug target: no

PharmGKB: 1 entry (VIP=true, CPIC=false)

CTD chemical–gene interactions

38 total (human), top 30 by PubMed support.

ChemicalActions (top 5)PubMed papers
Valproic Aciddecreases expression, increases methylation3
Estradiolaffects cotreatment, decreases expression2
Particulate Matterdecreases expression, increases abundance2
aristolochic acid Iincreases expression1
GSK-J4increases expression1
propionaldehydedecreases expression1
trichostatin Aaffects expression1
sodium arsenitedecreases expression, increases abundance1
cobaltous chlorideincreases expression1
ferrous chlorideincreases expression1
2,3-bis(3’-hydroxybenzyl)butyrolactoneaffects cotreatment, decreases expression1
pentanaldecreases expression1
abrineincreases expression1
2-(1H-indazol-4-yl)-6-(4-methanesulfonylpiperazin-1-ylmethyl)-4-morpholin-4-ylthieno(3,2-d)pyrimidineincreases expression, increases response to substance1
NSC 689534affects binding, increases expression1
(+)-JQ1 compoundincreases expression1
Sunitinibincreases expression1
Air Pollutantsdecreases expression, increases abundance1
Arsenicdecreases expression, increases abundance1
Berberinedecreases expression1
Bilirubinincreases expression1
Cisplatinincreases expression1
Copperaffects binding, increases expression1
Coumestrolaffects cotreatment, decreases expression1
Dieldrinincreases expression1
Dimethyl Sulfoxideincreases expression1
Hydrogen Peroxideaffects expression1
Silicon Dioxideincreases expression1
Smokedecreases expression1
Thiramincreases expression1

Clinical trials (associated diseases)

0 trials via MONDO — disease-level, not drug-specific.

No linked Atlas pages yet — the cross-entity mesh grows as the corpus expands.