For example, IFNγ has seemingly opposing effects on tumor cell viability in vitro and in vivo: the cytostatic effects of IFNγ largely inhibit tumor cell growth in vitro, whereas in vivo, the induction of PD-L1 by IFNγ provides a strong, cytoprotective effect that overcomes those inhibitory effects (16, 65, 66). Here, IFNG is linked to neoplasm.