It can involve different proto-oncogenes, tumor suppressor genes, and also epigenetic changes in the DNA.[3–5] Alternative pathways and more importantly, cross-talk among these pathways, which are directly responsible for the development and progression of CRC, have been discovered recently due to the efforts and advances made in the field of molecular biology.[6, 7] The inactivation of the tumor suppressor gene, p53, and the activation of the proto-oncogene, K-ras, are thought to be particularly important determinants of tumor initiation and progression among the genes characterized to date. The gene discussed is KRAS; the disease is colorectal carcinoma.