# MAGE-A4

Source: https://onco.cc/targets/mage-a4/  
OnCo record `mage-a4` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A protein normally only in testis that some sarcomas and other tumours switch on; T cells can be engineered to recognise fragments of it.

## Summary

MAGE-A4 is a cancer-testis antigen: an intracellular protein normally confined to testis that some tumours switch back on. It is presented on the cell surface only as peptide fragments in HLA, chiefly HLA-A*02, so it cannot be reached by antibodies or conventional CAR-T and is targetable only through T-cell receptor based approaches. Afamitresgene autoleucel (Tecelra), the first TCR-T therapy approved for a solid tumour (synovial sarcoma, 2024), recognises a MAGE-A4 peptide. Expression is seen in roughly 60 to 80 percent of synovial sarcomas and in myxoid liposarcoma, with subsets of squamous lung, ovarian and gastric cancers, but patients must also carry HLA-A*02, which about 40 to 45 percent of the population do. Durability of responses and extension beyond sarcoma are the open questions. Think of it as a hidden protein that engineered T cells can be taught to spot in fragments.

## Fields

- Kind: Target
- Last checked: 2026-09-04
- Tags: tcr-target
- Symbol: MAGEA4
- Class: other
- Biology: Intracellular; presented as peptide-HLA complex.
- Where found: Synovial sarcoma; Myxoid liposarcoma; NSCLC, ovarian, gastric (subsets)

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/MAGEA4
- Wikipedia: https://en.wikipedia.org/wiki/MAGEA4

## Connected records

- cancers: [Melanoma](https://onco.cc/cancers/melanoma/), [Sarcomas (soft tissue, bone, GIST)](https://onco.cc/cancers/sarcoma/)
- drugs: [Afamitresgene autoleucel](https://onco.cc/drugs/afamitresgene-autoleucel/)
- ideas: [Extending sarcoma TCR-T beyond HLA-A*02](https://onco.cc/ideas/idea-tcr-t-beyond-hla-a2/)
- technologies: [TCR-T cell therapy](https://onco.cc/technologies/tcr-t/)
- companies: [TScan Therapeutics](https://onco.cc/companies/tscan/)
- roadmaps: [Cell therapy roadmap: CD19 CAR-T → solid tumours → in vivo CAR](https://onco.cc/roadmaps/cell-therapy-roadmap/)
- people: [Sandra P. D'Angelo](https://onco.cc/people/sandra-dangelo/)
- pathways: [Antigen presentation & immune editing](https://onco.cc/pathways/antigen-presentation-immunoediting/)
- key papers: [SPEARHEAD-1: afamitresgene autoleucel, the first engineered T-cell receptor therapy approved for a solid tumour, in synovial sarcoma](https://onco.cc/key-papers/paper-spearhead-1-lancet-2024/)
- terms: [SS18::SSX fusion (synovial sarcoma)](https://onco.cc/terms/ss18-ssx-fusion/)
- targets: [HLA-A](https://onco.cc/targets/hla-a/)

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JSON: https://onco.cc/api/v1/entities/mage-a4.json