PDCD1 and melanoma: Further evidence supporting a potential added benefit from PD-1 inhibition to NY-ESO-1 targeted immunotherapy comes from NY-ESO-1157–165 peptide vaccination of melanoma patients, demonstrating an upregulation of the T cell inhibitory molecules PD-1, Tim-3 and BTLA in NY-ESO-1 CD8+ T cells (140–143).