RhoBTB3 is an atypical Rho GTPase that appears to have different functions compared to other RhoBTBs, such as RhoBTB1 and RhoBTB2. RhoBTB3 is only found in vertebrates and is a Rab9-regulated ATPase, rather than a GTPase, that participates in transport vesicle docking at the Golgi complex [].