EGFR and malignant colon neoplasm: In colon cancer, somatic KRAS mutations, located mainly in codon 12 and 13 of exon 2, have been reported to lead to a more aggressive and invasive tumor and have been associated with resistance to anti-epidermal growth factor receptor (EGFR) monoclonal antibodies such as cetuximab and panitumumab [18,55].