EGFR and colorectal carcinoma: It is currently believed that the pathogenesis of CRC is mainly related to the abnormality of five cell signal pathways: epidermal growth factor receptor (EGFR) signal pathway (including MAPK and PI3K signal pathway), Wnt/β-catenin signal pathway, Notch signal pathway, p53 signal pathway and Transforming growth factor-beta (TGF-β) signal pathway (30).