Studies of Weber et al. (including patients with melanoma who have progressed after being treated with ipilimumab and BRAF inhibitors) [24] and Robert et al. [25] (including metastatic melanoma patients, negative for BRAF mutation, not treated previously) reported that checkpoint inhibitors have been particularly successful in melanoma, with the highest response rates to single-agent PD-1/PD-L1 inhibition. Here, CD274 is linked to metastatic melanoma.