EGFR and colorectal cancer: Prior studies have pinpointed several tumor-associated targets including carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5, referred to as CEA) [14,15], epithelial cell adhesion molecule (EpCAM) [16,17], mesenchymal–epithelial transition factor (c-MET) [18,19,20], and epidermal growth factor receptor (EGFR) [21,22], which are overexpressed in most colorectal tumors and serve as key biomarkers in colorectal cancer (CRC).