CD274 and melanoma: To date, expression of PD-L1 is detected in multiple solid tumors, including melanoma, lung, breast, and ovarian cancers, as well as in myeloma, T cell lymphoma, etc. (Brown et al., 2003; Wherry et al., 2003; Ghebeh et al., 2006; Hamanishi et al., 2007; Liu et al., 2007; Hino et al., 2010).