CD274 and melanoma: Glycosylated PD-L1 is found in various cancer cell types, including melanoma, and breast, lung, and colon cancers, and exhibits a heterogeneous pattern on Western blots as indicated by a range of bands at ~ 50 kDa whereas the non-glycosylated form of PD-L1 is detected at ~ 33 kDa [23] (Fig. 1).