RAS viral (r-ras) oncogene homolog 2 isoform a, also known as RRAS2, belongs to the Ras like GTPase family that cycle between GTP-bound active and GDP-bound inactive states at the cytoplasmic face of the plasma membrane. It is implicated in the pathogenesis of human cancers. Thus, overexpression of active RRAS2 in EpH4 cells induces tumorigenicity through the phosphoinositide 3-kinase, p38 MAPK, and mTOR pathways, and these cells lose their sensitivity to the normal growth inhibitory role of TGF-beta.