PDCD1 and metastatic melanoma: In metastatic melanoma, PD-1, p = 1.48e−148, Pearson’s rho = 0.917; LAG3, p = 4.28e−163, Pearson’s rho = 0.931; IDO1, p = 2.38e−53, Pearson’s rho = 0.690) (Figure S8 in Supplementary Material).