Activated Rab5 on endocytosed vesicles recruits phosphatidylinositol-3-phosphate [PtdIns(3)P], whereas Rab8 recruits PtdIns(4)P at the TGN and secretory vesicles by regulating the phosphoinositide phosphatase OCRL (oculocerebrorenal syndrome of Lowe) (60). Here, OCRL is linked to oculocerebrorenal syndrome.