As for the treatments of melanoma, over the past decades, the management of melanoma has rapidly developed with the introduction of novel drug classes, such as BRAF and MEK pathway-targeted inhibitors and targeting immune check-point inhibitors consisting of CTLA-4, PD-1, PD-L1, and PD-L2 [32, 36, 51, 52]. Here, PDCD1LG2 is linked to melanoma.