CD274 and neoplasm: After EGFR is activated, it can promote the expression of tumor immune checkpoints, such as PD-L1, tumor cell proliferation, angiogenesis, and invasion, through its downstream effectors, including the phosphoinositide 3-kinase/protein kinase B, mitogen-activated protein kinase, rat sarcoma virus/rapidly accelerated fibrosarcoma/mitogen-activated extracellular signal-regulated kinase/extracellular signal-regulated kinase, Janus kinase/signal transducer and activator of transcription, and phospholipase C γ 1/protein kinase C pathways (17, 19).