RAB23 belongs to the Rab family of proteins and is restricted to the cytoplasmic side of the cell membrane. RAB23 takes part in intracellular protein transportation and signal transduction facilitated by small GTPases. RAB23 is a vital negative regulator of the Sonic hedgehog signaling pathway. Alterations in the gene encoding RAB23 are the origin for Carpenter syndrome a disorder which can cause obesity， cardiac defects， polysyndactyly and craniosynostosis.
