Background/Objectives: Metastatic colorectal cancer (mCRC) is mainly treated with 5-Fluoro-Uracil (5-FU), Oxaliplatin and Irinotecan chemotherapies and anti-Epidermal Growth Factor Receptor (EGFR) or anti-Vascular Endothelial Growth Factor (VEGF) targeted therapies. The gene discussed is EGFR; the disease is metastatic colorectal cancer.