Primary and acquired resistance have also been reported to occur in patients challenged with immune checkpoint inhibitor therapies and found to be associated with different mechanisms: poor immunogenicity, impaired maturation of dendritic cells (DCs), altered expression levels of the immunosuppressive marker PD-L1, insufficient T cell activation, antigen-presenting cell dysfunction, loss-of-function mutations in genes involved in antitumor signals (interferon-γ, IFN-γ), melanoma cell dedifferentiation and phenotypic plasticity [20,23,47,49,50,51]. Here, CD274 is linked to melanoma.