Mutations in MYO5B encoding Myosin 5b, which acts as a molecular motor not only for Rab11a, but also Rab11b, Rab25, and Rab8, cause MicroVillus Inclusion Disease (MVID) in which malabsorption results from the absence of the intestinal brush border [69]. The gene discussed is RAB25; the disease is microvillus inclusion disease.