EGFR and colorectal carcinoma: Several pathways, including Cadherin-catenin system, integrins, matrix metalloproteinases (MMPs), epidermal growth factor receptor (EGFR) signaling pathways (including the RAS-RAF-MAPK and PI3K/AKT), and the c-Met and hepatocyte growth factor/scatter factor (HGF/SF) signaling cascade (including the Wnt pathway, the Ras pathway and the PI3K/AKT pathway) have shown being involved in the CRC metastasis [4–9].