PRF1 and cancer: For the perforin/granzyme pathway, it has been reported that ART-type drugs induce granzyme B expression in γδ T cells which derived from the peripheral blood mononuclear cells and cytotoxic T lymphocytes (CTLs), indicating that ART-type drugs directly act on cancer cells with concomitant effects on immune cells to induce tumor cell to undergo apoptosis [62,63].