CD274 and neoplasm: Mechanisms responsible for this antitumor effect include inhibition of tumor cell proliferation, migration, angiogenesis, and proinflammatory cytokine secretion, as well as proapoptotic effects, which may block c-MET downstream signaling in the AKT and ERK1/2 signaling pathways, and the PD-L1/PD-1 signaling pathway.