Programmed death-ligand-1 (PD-L1) is a critical immune checkpoint ligand expressed on the surface of tumor cells, and binding of PD-L1 to its receptor PD-1 on activated T cells inhibits anti-tumor immunity by reducing the proliferation, cytokine secretion, and cytotoxic ability of T cells (Okazaki and Honjo, 2007). Here, CD274 is linked to neoplasm.