# RSF1

Source: https://onco.cc/targets/rsf1/  
OnCo record `rsf1` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

RSF1 (Remodeling and spacing factor 1) is a protein that switches other genes on and off. The public catalogues list it as a drug target and a biomarker, and clinical evidence ties its variants to diagnosis, prognosis or drug response. Tied to Breast cancer.

## Summary

Regulatory subunit of the ATP-dependent RSF-1 and RSF-5 ISWI chromatin-remodeling complexes, which form ordered nucleosome arrays on chromatin and facilitate access to DNA during DNA-templated processes such as DNA replication, transcription, and repair. Binds to core histones together with SMARCA5, and is required for the assembly of regular nucleosome arrays by the RSF-5 ISWI chromatin-remodeling complex. Directly stimulates the ATPase activity of SMARCA1 and SMARCA5 in the RSF-1 and RSF-5 ISWI chromatin-remodeling complexes, respectively.

CIViC holds 1 clinical evidence item and 0 assertions across 1 variant, naming Tamoxifen.

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: remodeling and spacing factor 1; Remodeling and spacing factor 1; XAP8; RSF-1; p325; HBXAP
- Tags: cancer-genes-wave
- Symbol: RSF1
- Class: transcription
- Biology: Regulatory subunit of the ATP-dependent RSF-1 and RSF-5 ISWI chromatin-remodeling complexes, which form ordered nucleosome arrays on chromatin and facilitate access to DNA during DNA-templated processes such as DNA replication, transcription, and repair. Binds to core histones together with SMARCA5, and is required for the assembly of regular nucleosome arrays by the RSF-5 ISWI chromatin-remodeling complex. Directly stimulates the ATPase activity of SMARCA1 and SMARCA5 in the RSF-1 and RSF-5 ISWI chromatin-remodeling complexes, respectively. The RSF-1 ISWI chromatin remodeling complex has a lower ATP hydrolysis rate than the RSF-5 ISWI chromatin-remodeling complex. The complexes do not have the ability to slide mononucleosomes to the centre of a DNA template. Facilitates transcription of hepatitis B virus (HBV) genes by the pX transcription activator. Location: Nucleus (UniProt). Locus 11q14.1 (HGNC).
- Where found: Breast cancer: CIViC evidence names this disease

## 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; CIViC holds 1 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.

## Sources

- HGNC HGNC:18118: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:18118
- UniProt Q96T23: https://www.uniprot.org/uniprotkb/Q96T23/entry
- NCBI Gene 51773: https://www.ncbi.nlm.nih.gov/gene/51773
- Ensembl ENSG00000048649: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000048649

## Connected records

- collections: [CIViC](https://onco.cc/collections/civic/)
- cancers: [Breast cancer (all types)](https://onco.cc/cancers/breast-cancer/)

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JSON: https://onco.cc/api/v1/entities/rsf1.json