KRAS and colorectal carcinoma: In this sense, many studies have shown the relationship of KRAS gene with CRC, so that the K-Ras protein (first identified in Kirsten rat sarcoma virus) is a part of RAS/MAPK signaling pathway, and their function is through GTPase that acts like switch by converting the active GTP molecule to inactive GDP, which is essential in the cellular signal process that control the growth, maturation and cellular death (7).