# STAG2

Source: https://onco.cc/targets/stag2/  
OnCo record `stag2` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

STAG2 (Cohesin subunit SA-2) is a gene whose normal job is to hold cell growth in check. The public catalogues list it as a drug target, a tumour suppressor and a biomarker, and clinical evidence ties its variants to diagnosis, prognosis or drug response. Tied to Bladder & urothelial cancer, Sarcomas, Renal cell carcinoma and 5 more.

## Summary

Component of cohesin complex, a complex required for the cohesion of sister chromatids after DNA replication. The cohesin complex apparently forms a large proteinaceous ring within which sister chromatids can be trapped. At anaphase, the complex is cleaved and dissociates from chromatin, allowing sister chromatids to segregate.

CIViC holds 6 clinical evidence items and 0 assertions across 3 variants, naming Vemurafenib. Open Targets scores its association with cancer at 0.75 (direct and indirect evidence; datatypes literature 0.97, genetic association 0.00, somatic mutation 0.97). IntOGen calls it a driver in 19 cohorts (0 activating, 19 loss-of-function), covering Acute Myeloid Leukaemia, Bladder Urothelial Carcinoma, Renal Clear Cell Carcinoma, Ewing Sarcoma, Glioblastoma Multiforme, Lung Squamous Cell Carcinoma and others.

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: STAG2 cohesin complex component; Cohesin subunit SA-2; SA-2; SCC3B; SA2
- Tags: cancer-genes-wave
- Symbol: STAG2
- Class: tumor-suppressor
- Biology: Component of cohesin complex, a complex required for the cohesion of sister chromatids after DNA replication. The cohesin complex apparently forms a large proteinaceous ring within which sister chromatids can be trapped. At anaphase, the complex is cleaved and dissociates from chromatin, allowing sister chromatids to segregate. The cohesin complex may also play a role in spindle pole assembly during mitosis. Location: Nucleus; Chromosome; Chromosome, centromere (UniProt). Locus Xq25 (HGNC).
- Where found: Bladder & urothelial cancer: Open Targets association 0.66 with urinary bladder cancer (MONDO_0001187); CIViC evidence names this disease; Sarcomas: Open Targets association 0.62 with sarcoma (MONDO_0005089); Renal cell carcinoma: IntOGen driver in 2 cohorts (CCRCC, PRCC); Endometrial cancer: Open Targets association 0.52 with endometrial cancer (MONDO_0011962); IntOGen driver in 1 cohort (UCEC); Thyroid cancer: IntOGen driver in 1 cohort (WDTC); Breast cancer: Open Targets association 0.55 with breast cancer (MONDO_0007254)

## Notes

- Written by scripts/fetch-cancer-genes.ts from CIViC, Open Targets, IntOGen, HGNC and UniProt; the function text is UniProt's, condensed and in UK spelling. Roles: CIViC lists 1 therapies; IntOGen calls it a loss-of-function (LoF) driver in 19 cohorts; CIViC holds 6 clinical evidence items on its variants. Evidence tier "clinical-evidence" is the strongest of those signals.
- Prevalence not recorded: none of the sources gives a positivity rate.
- Diseases the sources name that have no OnCo cancer page yet, so they are not linked: Ewing Sarcoma Of Bone; Bladder Urothelial Papillary Carcinoma.

## Sources

- HGNC HGNC:11355: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:11355
- UniProt Q8N3U4: https://www.uniprot.org/uniprotkb/Q8N3U4/entry
- NCBI Gene 10735: https://www.ncbi.nlm.nih.gov/gene/10735
- Ensembl ENSG00000101972: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000101972

## Connected records

- collections: [CIViC](https://onco.cc/collections/civic/), [IntOGen](https://onco.cc/collections/intogen/), [Open Targets Platform](https://onco.cc/collections/open-targets/)
- cancers: [Bladder & urothelial cancer](https://onco.cc/cancers/urothelial/), [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/), [Endometrial cancer](https://onco.cc/cancers/endometrial/), [Leukaemia (all types)](https://onco.cc/cancers/leukaemia/), [Myeloproliferative neoplasms (PV, ET, myelofibrosis)](https://onco.cc/cancers/myeloproliferative-neoplasms/), [Renal cell carcinoma](https://onco.cc/cancers/rcc/), [Sarcomas (soft tissue, bone, GIST)](https://onco.cc/cancers/sarcoma/), [Thyroid cancer](https://onco.cc/cancers/thyroid/)

---
JSON: https://onco.cc/api/v1/entities/stag2.json