CD274 and cancer: PD-L1 expression correlates with MYC levels in numerous cancer types.213,338–341 In NSCLC for example, the knockdown of MYC using small interfering RNA results in reduced PD-L1 mRNA and protein expression.341 On the other hand, as previously highlighted, oncogenic KRAS enhances PD-L1 by negatively regulating TTP, and the restoration of TTP reduces PD-L1 expression.251 Other authors also studied KRAS-mediated PD-L1 upregulation in lung249,250 and pancreatic342 cancers.