Innate vs. Adaptive: PD-L1-mediated immune resistance by melanoma

Oncogenic driver mutations in several tumor types promote constitutive PD-L1 expression, a crucial ligand in PD-1-mediated tumor immune escape. Our studies in melanoma suggest a different mechanism-one of adaptive immune resistance in which PD-L1 expression is primarily driven by cytokine induction and is independent of BRAF mutational status.