VSIR and melanoma: They have shown weak or non-durable responses, however, according to results from phase I clinical trials whereby they were used as monotherapy.51, , –54 On the other hand, inhibitory immune checkpoints, namely T-cell immunoglobulin and mucinodomain containing-3 (TIM-3), T-cell immunoglobulin and ITIM domain (TIGIT), and V-domain immunoglobulin suppressor T-cell activation (VISTA), have also been targets of interest in melanoma.55