PRF1 and neoplasm: (2) The activated T cells (L1, L5) produce cytotoxic granules like Granzyme B and K and perforin, which promote tumor death, chemotactic factors like CCL5 and XCL1/2, which signal to cDCs and/or T cells in the blood to enter the tumor microenvironment, and IFN-γ, which activates these incoming cDCs.