Melanoma patients that responded to anti‐PD‐L1 treatment had elevated baseline serum IFN‐γ expression, as well as IFN‐γ‐inducible gene expression.16 The expression of both IFN‐γ‐10 and expanded immune‐28 genes were significantly associated with clinical response in the KEYNOTE‐001 trial.42 Another study showed that the IFN‐γ‐responsive gene expression profiles were necessary, but not always sufficient, for clinical benefit of PD‐1 blockade.43 The correlation between immune gene signatures and response to checkpoint blockade needs more exploration. Here, IFNG is linked to melanoma.