Cancer colon is the third most common cancer in the world, constituting 8.9% of all cancers and the second leading cause of cancer-related death in the Western world. The disease is more common in developed than in developing countries and this is attributed to differences in diet. In USA colorectal cancer constitutes 9.5% of all cancers, whereas, in Egypt it constitutes 6.5% of all cancers. The prognosis of metastatic colorectal cancer (mCRC) patients remains poor regardless of the advances obtained in recent years with new therapeutic agents, surgical procedures, and diagnostic methods. Recent insights into the molecular pathogenesis of colorectal cancer have given rise to specific target-directed therapies, including monoclonal antibodies against epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF). These drugs have been approved as second and third line therapies for metastatic colorectal cancer (mCRC) . Ras constitute a family of proto-oncogenes encoding small G-proteins with a molecular weight of 21 KDa. Three different members contribute to the Ras gene family known as Harvey Ras (H-Ras), Kirsten Ras (K-Ras) and N-Ras.