Ras-related protein Rab-6B (RAB6B) is a member of the Rab6 family of the small GTPase superfamily. The Rab6 subfamily consists of 3 different isoforms: Rab6A, Rab6A’ and Rab6B. Both Rab6A and Rab6A’ are ubiquitously expressed while Rab6B is mainly expressed in brain. Rab6 is a main regulator in the retrograde transfer from endosomes via the Golgi to the ER and may act in retrograde tansport in neuronal cells.