The small GTPases Rab are key regulators of intracellular membrane trafficking, from the formation of transport vesicles to their fusion with membranes. Rabs cycle between an inactive GDP-bound form and an active GTP-bound form that is able to recruit to membranes different set of downstream effectors directly responsible for vesicle formation, movement, tethering and fusion (By similarity). RAB25 regulates epithelial cell differentiation, proliferation and survival, thereby playing key roles in tumorigenesis (PubMed:17925226). Promotes invasive migration of cells in which it functions to localize and maintain integrin alpha-V/beta-1 at the tips of extending pseudopodia (PubMed:17925226). Involved in the regulation of epithelial morphogenesis through the control of CLDN4 expression and localization at tight junctions (By similarity). May selectively regulate the apical recycling pathway (By similarity). Together with MYO5B regulates transcytosis (By similarity). {ECO:0000250|UniProtKB:E2RQ15, ECO:0000250|UniProtKB:P46629, ECO:0000250|UniProtKB:P61106, ECO:0000250|UniProtKB:Q9WTL2, ECO:0000269|PubMed:17925226}. This is the function of Ensembl gene identifier ENSG00000132698 (RAB25, RAB25, member RAS oncogene family).