PRF1 and cancer: Specifically, we checked the predictability of three pan-cancer T cell immune signatures for immunotherapy including the exhausted T-cell signature (average expression of PDCD1, CTLA4, LAG3, HAVCR2, and TIGIT in cytotoxic T cells; ref. 43), the cytolytic T-cell signature (average expression of GZMA and PRF1 in cytotoxic T cells; ref. 44), and CXCL13 expression in cytotoxic T cells (45).