PD-L1 expression has been shown to identify melanoma patients who are more likely to respond to PD-1 inhibitors.590 However, it is not recommended to take PD-L1 expression into account for treatment decisions because of the imperfect correlation between PD-L1 expression and clinical benefits from PD-1 inhibitors.525,591 Higher tumor mutational burden is associated with better response to ICBs, which is thought to enhance antitumor immune response through augmenting neoantigen formation. This evidence concerns the gene CD274 and melanoma.