CD274 and cancer: They change energy metabolism, adapt to hypoxia by enhancing the glycolytic system, promote proliferation by activating cell cycle signaling pathways, form new blood vessels to supply nutrition, acquire the ability to metastasize to other organs via blood and lymph fluids, acquire immune evasion ability by expressing immune checkpoint molecules such as PD-L1, and develop cancer stem cells that show resistance to chemotherapy [4,5,6,7].