EGFR and colorectal carcinoma: The epidermal growth factor receptor (EGFR), a tyrosine kinase receptor belonging to the ErbB family, is overexpressed in 25%–80% of CRCs and has been found to play a major role in the pathogenesis of CRC by inducing downstream signaling pathways such as the phosphatidylinositol-3-kinase/Akt and Ras/Raf/mitogen-activated protein kinase (MAPK) pathways, which are crucial in the regulation of cell growth, proliferation, apoptosis, invasion, migration, and angiogenesis [3].