GZMB and cancer: Killing of cancer cells by NK cells is also mediated by the cytolytic proteins perforin, granzymes as well as TRAIL, all inducing apoptosis in target cells.33, 34, 35 Of note, we found granzyme B-induced apoptosis and caspase-7 activation to be reduced by miR-519a-3p (Figures 4a and b).