Paradoxially, however, the expression of several well-known inhibitory receptors, including CTLA-4, PDCD1 (PD-1), TIGIT, IDO1, LAG3, ADORA2A and VTCN1, was similar between TMBhigh and TMBlow tumors, corroborating that in general, the expression of immune checkpoints and TMB are independent biomarkers in skin melanoma. This evidence concerns the gene IDO1 and cutaneous melanoma.