Similarly, ranking these melanoma cell lines by MITF expression (Fig. 9B) revealed significantly higher PD-L1 expression among cell lines with lower MITF levels (Fig. 9C; Mann–Whitney U test, P < 0.05), indicating that whilst not universal, there is a tendency for higher IFNγ-induced PD-L1 expression among less differentiated melanoma cells. This evidence concerns the gene IFNG and melanoma.