RhoA , RhoB , RhoC is a small G protein of the Rho family. Regulates a signal transduction pathway linking plasma membrane receptors to the assembly of focal adhesions and actin stress fibers. The three mammalian Rho proteins (A, B and C) are approximately 30% homologous to Ras and are expressed in a wide range of cell types. Both Ras p21 and Rho p21, as well as other members of the Ras superfamily, contain a carboxy terminal CAAX sequence (C, cysteine, A, aliphatic amino acid, X, any amino acid) which in the case of Ras has been shown to be essential for correct localization and function.