Programmed death ligand-1 (PD-L1, CD274, and B7-H1), which is a transmembrane glycoprotein expressed mainly on antigen presenting cells (APCs) and tumor cells, inhibits activated T-cells by binding to their inhibitory receptor, PD-1, in the tumor microenvironment (Tamura et al., 2001; Selenko-Gebauer et al., 2003; Zang et al., 2007). Here, CD274 is linked to neoplasm.