# B7-H4 (VTCN1)

Source: https://onco.cc/targets/b7h4/  
OnCo record `b7h4` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

B7-H4 is a checkpoint-like protein that many breast, ovarian and endometrial tumours carry on their surface. Antibody-drug conjugates such as puxitatug samrotecan and HS-20089 use it as a docking site to deliver a chemotherapy payload.

## Summary

VTCN1 (chromosome 1p13.1-p12) encodes B7-H4, a ligand that negatively regulates T-cell-mediated immunity by inhibiting T-cell activation, proliferation, cytokine production and the development of cytotoxicity; on tumour macrophages it works with regulatory T cells to suppress tumour-antigen-specific T-cell immunity, and it promotes epithelial cell transformation (UniProt Q7Z7D3). In OnCo it is the surface target of two topoisomerase I payload antibody-drug conjugates: puxitatug samrotecan, in triple-negative breast, ovarian and endometrial cancer, and HS-20089, a humanised IgG1 with a protease-cleavable linker and a drug-to-antibody ratio of about 6, in phase 3 for ovarian and endometrial cancer.

## Fields

- Kind: Target
- Last checked: 2026-09-22
- Also known as: B7-H4; B7H4; B7x; B7S1; V-set domain containing T cell activation inhibitor 1
- Tags: wave5-target
- Symbol: VTCN1
- Class: checkpoint
- Biology: The puxitatug samrotecan record calls B7-H4 a checkpoint-like protein enriched in breast, ovarian and endometrial cancers; in the corpus it is used as an ADC address rather than as a checkpoint to block.
- Where found: Triple-negative breast cancer; Ovarian and endometrial cancer; Tumour-associated macrophages

## Notes

- Prevalence not recorded in this wave: HGNC and UniProt carry no positivity rates and no other source was consulted.

## Sources

- HGNC HGNC:28873: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:28873
- UniProt Q7Z7D3: https://www.uniprot.org/uniprotkb/Q7Z7D3/entry
- NCBI Gene 79679: https://www.ncbi.nlm.nih.gov/gene/79679

## Connected records

- targets: [Topoisomerase I (TOP1)](https://onco.cc/targets/top1/)
- cancers: [Endometrial cancer](https://onco.cc/cancers/endometrial/), [Ovarian cancer](https://onco.cc/cancers/ovarian/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- technologies: [Antibody-drug conjugate (ADC)](https://onco.cc/technologies/adc/)
- drugs: [HS-20089](https://onco.cc/drugs/hs-20089/), [Puxitatug samrotecan](https://onco.cc/drugs/puxitatug-samrotecan/)
- pathways: [Cold tumours: immune deserts and exclusion](https://onco.cc/pathways/immune-desert-exclusion/), [PD-1 / PD-L1 immune checkpoint & T-cell activation](https://onco.cc/pathways/pd1-checkpoint/)

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JSON: https://onco.cc/api/v1/entities/b7h4.json