TGFA and small cell lung carcinoma: TGFA is highly expressed in tumor tissues such as bladder cancer, oral cancer, pancreatic cancer, and small cell lung cancer, accelerating cell proliferation, invasion, and EMT (epithelial–mesenchymal transition), and is closely related to the prognosis of tumor patients (Kang et al., 2005; Liu et al., 2017; Hao et al., 2018; Zhang et al., 2021).