KRAS and cancer: Ras family is the root of the small GTPase superfamily according to the phylogenetic reconstruction analysis, so the small GTPase family is also known as Ras superfamily.8 Ras family consists of 36 members falling into seven subfamilies: Ras (KRAS4A, KRAS4B, NRAS, and HRAS), Ral, Rheb, Rap, Rad, Rit and DIRAS, which serve as central nodes of a wide range of signaling pathways controlling cell survival, proliferation, differentiation, migration, and adhesion.9,10 As the first human oncogene to be identified, Ras has been well established as an oncogenic driver in multiple human cancers.