Importantly, IFNγ is known to induce PD-L1 expression in melanoma cells through the JAK1/2-STAT1/3-IRF1 axis [27, 36], and there are indications that some melanoma cell lines display increased IFNγ-induced PD-L1 expression when dedifferentiated [21, 37]. Here, IRF1 is linked to melanoma.