Despite the inability of SCC VII cells to express MHC-II, cells expressing TCR 1 within the TME were enriched for transcripts associated with cytotoxicity (prf1, gzmc, gzme and gzmf), suggesting that this transcriptomic signature may be broadly associated with local CD4+ effector T cell differentiation even in cases where such cells cannot directly engage tumor cells. The gene discussed is PRF1; the disease is neoplasm.