This gene ARHGAP4 encodes a member of the rhoGAP family, rho GTPase-activating protein 4. Proteins of the rhoGAP family play a role in the regulation of small GTP-binding proteins belonging to the RAS superfamily. The protein encoded by the orthologous gene in rat is localized to the Golgi complex and can redistribute to microtubules. The rat protein stimulates the activity of some Rho GTPases in vitro. Genomic deletions of this gene and a neighboring gene have been found in patients with nephrogenic diabetes insipidus [taken from NCBI Entrez Gene ID: 393].