Glycoproteins were examined in pre-treatment plasma samples from metastatic melanoma patients undergoing different ICI therapies including first or second-line anti-PD-1 monotherapy (pembrolizumab or nivolumab) or anti-PD-1/anti-CTLA-4 combination therapy (nivolumab/ipilimumab). This evidence concerns the gene PDCD1 and metastatic melanoma.