The Rho subfamily of Ras-related GTPases controls multiple aspects of cell function, including cytoskeletal rearrangement, nuclear signaling and cell growth. Rho V (ras homolog gene family, member V), also known as Rho GTPase-like protein ARHV, CHP or WRCH2 (Wnt-1 responsive Cdc42 homolog 2), is a 236 amino acid protein that controls the actin cytoskeleton through activation of the JNK pathway. A member of the Rho family and small GTPase superfamily, Rho V functions as a lipid anchor at the cytoplasmic side of the cell membrane and is expressed in placenta, pancreas and fetal brain. Rho V is implicated in cell transformation and is encoded by a gene located on human chromosome 15, which houses over 700 genes and comprises nearly 3% of the human genome. Angelman syndrome, Prader-Willi syndrome, Tay-Sachs disease and Marfan syndrome are all associated with defects in chromosome 15-localized genes.