CD274 and melanoma: Immune-based therapies have shown significant therapeutic efficacy in numerous tumor types, including advanced melanomas and non-small cell lung cancers.[4–7] Immune-induced tumor programmed cell death-ligand 1 (PD-L1) expression is considered to be an adaptive immune resistance mechanism for tumor cells in response to immune challenge.[8–10] Sufficient T cell infiltration is essential for response to PD-L1 blockade.