ZPLD1
gene geneOn this page
Summary
ZPLD1 (zona pellucida like domain containing 1, HGNC:27022) is a protein-coding gene on chromosome 3q12.3, encoding Zona pellucida-like domain-containing protein 1 (Q8TCW7). Glycoprotein which is a component of the gelatinous extracellular matrix in the cupulae of the vestibular organ.
Predicted to act upstream of or within vestibular reflex. Predicted to be located in cytoplasmic vesicle membrane and extracellular region. Predicted to be active in cell surface and extracellular space.
Source: NCBI Gene 131368 — RefSeq curated summary.
At a glance
- GWAS associations: 14
- Clinical variants (ClinVar): 74 total
- MANE Select transcript:
NM_001329788
Identifiers
Gene identifiers
| Field | Value |
|---|---|
| HGNC ID | HGNC:27022 |
| Approved symbol | ZPLD1 |
| Name | zona pellucida like domain containing 1 |
| Location | 3q12.3 |
| Locus type | gene with protein product |
| Status | Approved |
| Ensembl gene | ENSG00000170044 |
| Ensembl biotype | protein_coding |
| OMIM | 615915 |
| Entrez | 131368 |
Gene structure
Transcript identifiers
Ensembl transcripts: 4 — 3 protein_coding, 1 protein_coding_CDS_not_defined
ENST00000306176, ENST00000466937, ENST00000478083, ENST00000491959
RefSeq mRNA: 2 — MANE Select: NM_001329788
NM_001329788, NM_175056
CCDS: CCDS2947, CCDS87115
Canonical transcript exons
ENST00000466937 — 12 exons
| Exon | Start | End |
|---|---|---|
| ENSE00001072972 | 102477012 | 102477041 |
| ENSE00001072973 | 102470394 | 102470502 |
| ENSE00001072974 | 102457781 | 102457853 |
| ENSE00001072975 | 102456193 | 102456374 |
| ENSE00001072976 | 102462281 | 102462378 |
| ENSE00001072978 | 102468964 | 102469135 |
| ENSE00001072980 | 102452919 | 102453139 |
| ENSE00001161810 | 102477443 | 102479841 |
| ENSE00001209460 | 102464171 | 102464251 |
| ENSE00001824084 | 102435015 | 102435154 |
| ENSE00001924477 | 102436860 | 102436973 |
| ENSE00003674609 | 102438480 | 102438593 |
Expression profiles
Bgee: expression breadth broad, 71 present calls, max score 82.97.
Top tissues by expression
216 total, by Bgee expression score (0-100, higher = more expressed):
| Tissue | Anatomy ID | Expression score | Quality |
|---|---|---|---|
| secondary oocyte | CL:0000655 | 82.97 | gold quality |
| male germ line stem cell (sensu Vertebrata) in testis | CL:0000089 ∩ UBERON:0000473 | 75.81 | silver quality |
| islet of Langerhans | UBERON:0000006 | 75.41 | gold quality |
| oocyte | CL:0000023 | 72.66 | gold quality |
| primordial germ cell in gonad | CL:0000670 ∩ UBERON:0000991 | 72.32 | gold quality |
| gall bladder | UBERON:0002110 | 68.65 | gold quality |
| decidua | UBERON:0002450 | 55.66 | gold quality |
| metanephros cortex | UBERON:0010533 | 51.45 | gold quality |
| stromal cell of endometrium | CL:0002255 | 51.33 | gold quality |
| duodenum | UBERON:0002114 | 50.26 | gold quality |
| buccal mucosa cell | CL:0002336 | 50.01 | gold quality |
| pancreas | UBERON:0001264 | 48.55 | gold quality |
| metanephros | UBERON:0000081 | 48.11 | gold quality |
| adult mammalian kidney | UBERON:0000082 | 46.20 | gold quality |
| colonic epithelium | UBERON:0000397 | 46.12 | gold quality |
| sural nerve | UBERON:0015488 | 45.19 | gold quality |
| endometrium | UBERON:0001295 | 44.49 | gold quality |
| kidney | UBERON:0002113 | 44.39 | gold quality |
| cortex of kidney | UBERON:0001225 | 43.58 | gold quality |
| skeletal muscle tissue of rectus abdominis | UBERON:0004511 | 43.37 | gold quality |
| oviduct epithelium | UBERON:0004804 | 43.29 | silver quality |
| placenta | UBERON:0001987 | 42.68 | silver quality |
| monocyte | CL:0000576 | 42.65 | silver quality |
| sperm | CL:0000019 | 42.16 | silver quality |
| lower lobe of lung | UBERON:0008949 | 42.10 | silver quality |
| leukocyte | CL:0000738 | 41.92 | silver quality |
| hindlimb stylopod muscle | UBERON:0004252 | 41.90 | gold quality |
| smooth muscle tissue | UBERON:0001135 | 41.82 | gold quality |
| vastus lateralis | UBERON:0001379 | 41.41 | gold quality |
| quadriceps femoris | UBERON:0001377 | 41.37 | gold quality |
Single-cell (SCXA)
Detected in 1 experiment(s), a significant marker in 1.
| Experiment | Marker? | Max mean expression |
|---|---|---|
| E-ANND-3 | yes | 6.36 |
Regulation
Is transcription factor: no
miRNA regulators (miRDB)
94 targeting ZPLD1, top 30 by miRDB confidence (max_score; target_count = how many genes the miRNA targets in total — lower means more specific):
| miRNA | Max score | Avg score | miRNA target_count |
|---|---|---|---|
| HSA-MIR-3646 | 100.00 | 73.56 | 5283 |
| HSA-MIR-3163 | 100.00 | 77.23 | 8605 |
| HSA-MIR-5692B | 100.00 | 71.32 | 2622 |
| HSA-MIR-5692C | 100.00 | 71.32 | 2622 |
| HSA-MIR-3662 | 99.99 | 73.82 | 5684 |
| HSA-MIR-4531 | 99.99 | 69.70 | 3181 |
| HSA-MIR-548C-3P | 99.99 | 74.01 | 7587 |
| HSA-MIR-3185 | 99.99 | 68.12 | 1959 |
| HSA-MIR-4500 | 99.99 | 72.72 | 2367 |
| HSA-MIR-19A-3P | 99.98 | 75.33 | 2762 |
| HSA-MIR-19B-3P | 99.98 | 75.44 | 2754 |
| HSA-MIR-12136 | 99.98 | 72.81 | 5713 |
| HSA-MIR-507 | 99.97 | 70.11 | 1915 |
| HSA-MIR-551B-5P | 99.96 | 71.28 | 3493 |
| HSA-MIR-557 | 99.96 | 70.01 | 1640 |
| HSA-MIR-23C | 99.95 | 73.92 | 3192 |
| HSA-MIR-23A-3P | 99.95 | 74.24 | 3163 |
| HSA-MIR-23B-3P | 99.95 | 74.24 | 3163 |
| HSA-MIR-9983-3P | 99.94 | 71.48 | 3631 |
| HSA-MIR-9718 | 99.94 | 68.91 | 918 |
| HSA-MIR-335-3P | 99.93 | 73.36 | 4958 |
| HSA-MIR-3119 | 99.92 | 71.34 | 2390 |
| HSA-MIR-6768-5P | 99.92 | 67.36 | 1942 |
| HSA-MIR-454-3P | 99.91 | 74.01 | 1925 |
| HSA-MIR-374A-5P | 99.90 | 71.34 | 2923 |
| HSA-MIR-374B-5P | 99.90 | 69.98 | 2734 |
| HSA-MIR-130A-3P | 99.90 | 73.31 | 1861 |
| HSA-MIR-130B-3P | 99.90 | 73.27 | 1850 |
| HSA-MIR-301A-3P | 99.90 | 73.15 | 1839 |
| HSA-MIR-301B-3P | 99.90 | 73.19 | 1836 |
Literature-anchored findings (GeneRIF, showing 2)
- this protein may be part of the complex signaling pathway implicated in cerebral cavernous malformation formation (PMID:18632209)
- associations revealed between genetic polymorphisms located in the flanking region of the ARID1B genes and hypoesthesia (PMID:23834954)
Cross-species orthologs
4 orthologs
| Organism | Symbol | Gene ID |
|---|---|---|
| danio_rerio | zpld1a | ENSDARG00000061835 |
| danio_rerio | zpld1b | ENSDARG00000063372 |
| mus_musculus | Zpld1 | ENSMUSG00000064310 |
| rattus_norvegicus | Zpld1 | ENSRNOG00000039517 |
Paralogs (5): TECTB (ENSG00000119913), OIT3 (ENSG00000138315), UMOD (ENSG00000169344), GP2 (ENSG00000169347), UMODL1 (ENSG00000177398)
Protein
Protein identifiers
Zona pellucida-like domain-containing protein 1 — Q8TCW7 (reviewed: Q8TCW7)
Alternative names: Cupulin
All UniProt accessions (1): Q8TCW7
UniProt curated annotations — full annotation on UniProt →
Function. Glycoprotein which is a component of the gelatinous extracellular matrix in the cupulae of the vestibular organ.
Subcellular location. Cytoplasmic vesicle membrane Secreted. Extracellular space. Extracellular matrix.
Tissue specificity. Detected in placenta, kidney, lung, pancreas and at very low level in other tissues.
Post-translational modifications. Proteolytically cleaved before the transmembrane segment to yield the secreted form found in the extracellular matrix of the cupula.
Isoforms (2)
| UniProt ID | Names | Canonical? |
|---|---|---|
| Q8TCW7-1 | 1 | yes |
| Q8TCW7-2 | 2 |
RefSeq proteins (2): NP_001316717, NP_778226 (=MANE)
Domains & families (InterPro)
| ID | Name | Type |
|---|---|---|
| IPR001507 | ZP_dom | Domain |
| IPR042235 | ZP-C_dom | Homologous_superfamily |
| IPR055355 | ZP-C | Domain |
| IPR055356 | ZP-N | Domain |
Pfam: PF00100, PF23344
UniProt features (22 total): disulfide bond 4, sequence variant 3, chain 2, glycosylation site 2, topological domain 2, compositionally biased region 2, signal peptide 1, site 1, splice variant 1, sequence conflict 1, transmembrane region 1, domain 1, region of interest 1
Structure
Experimental structures (PDB)
0 structures.
Predicted structure (AlphaFold)
| Model | pLDDT | Fraction very-high |
|---|---|---|
| AF-Q8TCW7-F1 | 77.56 | 0.38 |
Functional residue map
Curated UniProt residues grouped by drug-discovery relevance — catalytic, ligand-binding, modification, and mutation-validated positions. Source: UniProtKB sequence features.
Catalytic / active sites (1): 319–320 (cleavage)
Disulfide bonds (4): 44–155, 79–104, 235–296, 255–313
Glycosylation sites (2): 121, 164
Function
Pathways and Gene Ontology
Reactome pathways
0 pathways
MSigDB gene sets: 49 (showing top):
GOZGIT_ESR1_TARGETS_DN, GOCC_CELL_SURFACE, GOBP_REFLEX, POU3F2_02, chr3q12, SENGUPTA_NASOPHARYNGEAL_CARCINOMA_WITH_LMP1_UP, TEF_Q6, VDR_Q6, ZWANG_TRANSIENTLY_UP_BY_2ND_EGF_PULSE_ONLY, NABA_ECM_GLYCOPROTEINS, ZNF274_TARGET_GENES, MIR3662, MIR548AR_3P, MIR548F_3P, MIR548BC
GO Biological Process (1): vestibular reflex (GO:0060005)
GO Molecular Function (0):
GO Cellular Component (6): obsolete extracellular space (GO:0005615), cell surface (GO:0009986), cytoplasmic vesicle membrane (GO:0030659), extracellular region (GO:0005576), membrane (GO:0016020), cytoplasmic vesicle (GO:0031410)
GO top-level categories
Rollup of top GO terms by namespace:
| Category | Terms |
|---|---|
| cellular anatomical structure | 3 |
| reflex | 1 |
| vesicle membrane | 1 |
| cytoplasmic vesicle | 1 |
| cytoplasm | 1 |
| intracellular vesicle | 1 |
Protein interactions and networks
STRING
578 interactions, top by confidence (×1000):
| Protein A | Protein B | Partner UniProt | Score |
|---|---|---|---|
| ZPLD1 | BRICD5 | Q6PL45 | 566 |
| ZPLD1 | FNDC7 | Q5VTL7 | 523 |
| ZPLD1 | C10orf120 | Q5SQS8 | 520 |
| ZPLD1 | CUZD1 | Q86UP6 | 518 |
| ZPLD1 | FAM162B | Q5T6X4 | 495 |
| ZPLD1 | AKR1E2 | Q96JD6 | 491 |
| ZPLD1 | TRIM42 | Q8IWZ5 | 487 |
| ZPLD1 | C5orf47 | Q569G3 | 483 |
| ZPLD1 | GALNTL6 | Q49A17 | 472 |
| ZPLD1 | CIB3 | Q96Q77 | 461 |
| ZPLD1 | HS6ST3 | Q8IZP7 | 456 |
| ZPLD1 | OTOG | Q6ZRI0 | 446 |
| ZPLD1 | AGR3 | Q8TD06 | 435 |
| ZPLD1 | CCDC27 | Q2M243 | 433 |
| ZPLD1 | CLEC19A | Q6UXS0 | 431 |
IntAct
3 interactions, top by confidence:
| A | B | Type | Score |
|---|---|---|---|
| RARG | RARA | psi-mi:“MI:0914”(association) | 0.530 |
| ZPLD1 | CEACAM8 | psi-mi:“MI:0914”(association) | 0.350 |
BioGRID (18): CEACAM8 (Affinity Capture-MS), ZPLD1 (Affinity Capture-MS), GNPTAB (Affinity Capture-MS), LRRC16A (Affinity Capture-MS), RTN4 (Affinity Capture-MS), TMX1 (Affinity Capture-MS), SDF2L1 (Affinity Capture-MS), STEAP2 (Affinity Capture-MS), GNPTG (Affinity Capture-MS), FAM207A (Affinity Capture-MS), STEAP2 (Affinity Capture-MS), RTN4 (Affinity Capture-MS), TMX1 (Affinity Capture-MS), LRRC16A (Affinity Capture-MS), CEACAM8 (Affinity Capture-MS)
ESM2 similar proteins: A1A4K5, A7E2Z9, A8MWY0, A8WCC4, C0H9B6, C6KFA3, F1QR43, F1R520, O13097, O18756, O73874, O94923, O94985, P07224, P07225, P0C152, P13612, P19218, P24387, P24668, P26009, P53813, P98118, Q00651, Q08761, Q0VCT4, Q13822, Q16819, Q28CF8, Q3UZV7, Q5HYA8, Q64610, Q66IR0, Q6AY20, Q6BEA0, Q6F3F9, Q6Q0N0, Q86SQ4, Q8BGZ8, Q8TCW7
Diamond homologs: C0H9B6, P54097, Q66IR0, Q862Z3, Q8BGZ8, Q8TCW7, Q95JJ6, A2ARV4, B3EWY9, B5DFC9, C0HL13, G3V928, O08523, O35568, O42182, O57382, O64758, O73775, O75095, O75443, O88322, P06579, P07225, P07911, P14543, P15306, P19218, P23142, P25291, P27590, P35444, P35445, P35555, P35556, P35951, P48733, P48960, P49747, P53813, P55259
SIGNOR signaling
0 interactions.
Disease & clinical
Clinical variants and AI predictions
ClinVar
74 variants total. Per-class counts are floors (≥ shown; pagination cap):
| Classification | Count (floor) |
|---|---|
| Pathogenic | 0 |
| Likely pathogenic | 0 |
| Uncertain significance | 60 |
| Likely benign | 6 |
| Benign | 1 |
Top pathogenic / likely-pathogenic (0)
SpliceAI
5138 predictions. Top by Δscore:
| Variant | Effect | Δscore |
|---|---|---|
| 3:102324863:GTTCT:G | donor_gain | 1.0000 |
| 3:102324868:G:GG | donor_gain | 1.0000 |
| 3:102377682:G:GT | donor_gain | 1.0000 |
| 3:102438593:GGTA:G | donor_loss | 1.0000 |
| 3:102438594:G:GC | donor_loss | 1.0000 |
| 3:102438594:G:GG | donor_gain | 1.0000 |
| 3:102438595:T:G | donor_loss | 1.0000 |
| 3:102438598:GT:G | donor_gain | 1.0000 |
| 3:102452917:A:AG | acceptor_gain | 1.0000 |
| 3:102452918:G:GG | acceptor_gain | 1.0000 |
| 3:102453137:GTG:G | donor_gain | 1.0000 |
| 3:102453137:GTGGT:G | donor_loss | 1.0000 |
| 3:102453138:TGGTA:T | donor_loss | 1.0000 |
| 3:102453139:GGT:G | donor_loss | 1.0000 |
| 3:102453140:G:C | donor_loss | 1.0000 |
| 3:102456375:G:GG | donor_gain | 1.0000 |
| 3:102457852:AC:A | donor_gain | 1.0000 |
| 3:102457854:G:GG | donor_gain | 1.0000 |
| 3:102468947:C:G | acceptor_gain | 1.0000 |
| 3:102468955:A:AG | acceptor_gain | 1.0000 |
| 3:102468956:A:G | acceptor_gain | 1.0000 |
| 3:102468957:A:G | acceptor_gain | 1.0000 |
| 3:102468960:TTA:T | acceptor_loss | 1.0000 |
| 3:102468961:TAG:T | acceptor_loss | 1.0000 |
| 3:102468962:A:AG | acceptor_gain | 1.0000 |
| 3:102468962:AG:A | acceptor_loss | 1.0000 |
| 3:102468963:G:GG | acceptor_gain | 1.0000 |
| 3:102469132:GCCG:G | donor_gain | 1.0000 |
| 3:102469133:CCGGT:C | donor_loss | 1.0000 |
| 3:102469134:CGG:C | donor_loss | 1.0000 |
AlphaMissense
2720 scored. Top likely-pathogenic:
| Variant | Protein change | am_pathogenicity |
|---|---|---|
| 3:102452979:G:A | C56Y | 1.000 |
| 3:102456328:T:C | C155R | 1.000 |
| 3:102456329:G:A | C155Y | 1.000 |
| 3:102456330:T:G | C155W | 1.000 |
| 3:102464193:T:A | C235S | 1.000 |
| 3:102464193:T:C | C235R | 1.000 |
| 3:102464194:G:A | C235Y | 1.000 |
| 3:102464194:G:C | C235S | 1.000 |
| 3:102464195:C:G | C235W | 1.000 |
| 3:102469023:T:C | F274S | 1.000 |
| 3:102469043:T:C | F281L | 1.000 |
| 3:102469044:T:G | F281C | 1.000 |
| 3:102469045:T:A | F281L | 1.000 |
| 3:102469045:T:G | F281L | 1.000 |
| 3:102469088:T:A | C296S | 1.000 |
| 3:102469088:T:C | C296R | 1.000 |
| 3:102469089:G:A | C296Y | 1.000 |
| 3:102469089:G:C | C296S | 1.000 |
| 3:102469090:C:G | C296W | 1.000 |
| 3:102438563:T:A | C26S | 0.999 |
| 3:102438564:G:C | C26S | 0.999 |
| 3:102452942:T:A | C44S | 0.999 |
| 3:102452942:T:C | C44R | 0.999 |
| 3:102452943:G:A | C44Y | 0.999 |
| 3:102452943:G:C | C44S | 0.999 |
| 3:102452943:G:T | C44F | 0.999 |
| 3:102452944:T:G | C44W | 0.999 |
| 3:102452978:T:A | C56S | 0.999 |
| 3:102452978:T:C | C56R | 0.999 |
| 3:102452979:G:C | C56S | 0.999 |
dbSNP variants (sampled 300 via entrez): RS1000023602 (3:102445523 T>A,G), RS1000023668 (3:102408865 A>C), RS1000060112 (3:102395722 C>G,T), RS1000075740 (3:102388455 C>G), RS1000081226 (3:102446619 AG>A), RS1000138127 (3:102408615 T>C), RS1000155441 (3:102472120 A>G), RS1000168930 (3:102386593 T>A,C), RS1000238877 (3:102466610 G>A,T), RS1000254171 (3:102428540 T>C), RS1000262843 (3:102473357 C>A), RS1000278328 (3:102434087 A>G), RS1000281553 (3:102386332 C>A,G,T), RS1000282585 (3:102408784 T>C,G), RS1000313324 (3:102427015 T>C)
Disease associations
OMIM: gene MIM:615915 | disease phenotypes:
GenCC curated gene-disease
Mondo (0):
Orphanet (0):
HPO phenotypes
0 total (0 of 0 shown, HPO-id order):
GWAS associations
14 associations (top):
| Study | Trait | p-value |
|---|---|---|
| GCST001033_15 | Type 2 diabetes | 3.000000e-06 |
| GCST002090_5 | Sensory disturbances after bilateral sagittal split ramus osteotomy | 2.000000e-06 |
| GCST002938_10 | Copper levels | 9.000000e-07 |
| GCST003264_858 | Post bronchodilator FEV1/FVC ratio | 1.000000e-06 |
| GCST004579_3 | Waist-to-hip circumference ratio (alcohol intake interaction) | 2.000000e-06 |
| GCST006277_3 | Response to ranibizumab in age-related macular degeneration (exudative) | 2.000000e-06 |
| GCST007121_3 | Multiple sclerosis and C-reactive protein levels (pleiotropy) | 1.000000e-08 |
| GCST007122_2 | Multiple sclerosis and triglyceride levels (pleiotropy) | 1.000000e-08 |
| GCST010396_155 | Gut microbiota (bacterial taxa, hurdle binary method) | 2.000000e-06 |
| GCST012292_4 | Schizophrenia, bipolar disorder or recurrent major depressive disorder x sex interaction | 1.000000e-06 |
| GCST012295_5 | Schizophrenia, bipolar disorder or recurrent major depressive disorder x sex interaction | 2.000000e-06 |
| GCST012298_5 | Schizophrenia, bipolar disorder or major depressive disorder x sex interaction | 4.000000e-07 |
| GCST012299_9 | Schizophrenia, bipolar disorder or major depressive disorder x sex interaction (3df) | 5.000000e-06 |
| GCST012301_15 | Schizophrenia, bipolar disorder or major depressive disorder x sex interaction | 5.000000e-07 |
EFO canonical traits (9, from GWAS)
| EFO ID | Trait name |
|---|---|
| EFO:0005324 | post-operative sensory disturbance |
| EFO:0004713 | FEV/FVC ratio |
| EFO:0004343 | waist-hip ratio |
| EFO:0008348 | response to ranibizumab |
| EFO:0004458 | C-reactive protein measurement |
| EFO:0004530 | triglyceride measurement |
| EFO:0007874 | gut microbiome measurement |
| EFO:0004952 | disease recurrence |
| EFO:0008343 | sex interaction measurement |
Drugs & pharmacology
Drug and pharmacology data
Is drug target: no
PharmGKB: 1 entry (VIP=true, CPIC=false)
CTD chemical–gene interactions
24 total (human), top 24 by PubMed support.
| Chemical | Actions (top 5) | PubMed papers |
|---|---|---|
| Valproic Acid | affects cotreatment, decreases expression, decreases methylation | 6 |
| trichostatin A | decreases expression | 2 |
| Aflatoxin B1 | decreases methylation | 2 |
| methylmercuric chloride | decreases expression | 1 |
| bisphenol A | affects cotreatment, increases methylation | 1 |
| perfluorooctanoic acid | decreases expression | 1 |
| aflatoxin B2 | increases methylation | 1 |
| perfluorooctane sulfonic acid | decreases expression | 1 |
| perfluoro-n-nonanoic acid | decreases expression | 1 |
| 4-(5-benzo(1,3)dioxol-5-yl-4-pyridin-2-yl-1H-imidazol-2-yl)benzamide | affects cotreatment, decreases expression | 1 |
| dorsomorphin | affects cotreatment, decreases expression | 1 |
| bisphenol S | decreases methylation, affects cotreatment | 1 |
| (+)-JQ1 compound | decreases expression | 1 |
| Resveratrol | affects cotreatment, decreases expression | 1 |
| Fulvestrant | affects cotreatment, increases methylation, decreases methylation | 1 |
| Benzo(a)pyrene | decreases expression | 1 |
| Cadmium | decreases expression, increases abundance | 1 |
| Doxorubicin | decreases expression | 1 |
| Endosulfan | decreases expression | 1 |
| Plant Extracts | affects cotreatment, decreases expression | 1 |
| Tetrachlorodibenzodioxin | increases expression | 1 |
| Tobacco Smoke Pollution | increases expression | 1 |
| Medroxyprogesterone Acetate | increases expression | 1 |
| Cadmium Chloride | decreases expression, increases abundance | 1 |
Clinical trials (associated diseases)
0 trials via MONDO — disease-level, not drug-specific.
Related Atlas pages
No linked Atlas pages yet — the cross-entity mesh grows as the corpus expands.