IDO1 and melanoma: Among the top-ranked genes identified in the NanoString analysis of genes associated with melanoma responsiveness to ICT and its microenvironment (including immune-infiltrated cells) was a cluster of 10 genes implicated in the IFN-γ response [IFNG, STAT1, CCR5, CXCL9, CXCL10, CXCL11, IDO1, PRF1, GZMA, and HLA-D; (16)].