Similar findings could have been observed for melanoma [39], gastric [40], hepatocellular [41,42], urothelial [15], renal [16,43], ovarian [44], and lung cancers [12,14,39,45]: baseline soluble PD-L1 measurements can serve as a good prognostic marker for patient survival and increasing levels are associated with progressive disease. Here, CD274 is linked to melanoma.