Scientists Discover a Completely Unexpected Way T Cells Kill Cancer

Researchers found that lowering MHC class I can make cancer and transplanted cells more vulnerable to CD4+ T cell killing.

The death mechanism appears to involve ferroptosis, not the classic CD8-only pathway.

The result challenges the long-standing model that CD4+ T cells mainly act through MHC class II while CD8+ T cells respond to MHC class I.

The findings could open new directions for cancer immunotherapy and transplant-related care, including graft-versus-host disease.