Ras-related protein RAB25, also known as CATX-8, is a 23 kDa (unglycosylated) member of the small GTPase superfamily and RAB family of proteins. Human RAB25 is 213 amino acids (aa) in length. The mature chain runs from aa 1-210 with residues 211-213 constituting a propeptide. Residues 10-174 are noted to be RAB11-like. RAB11a, RAB11b, and RAB25 are closely related RAB proteins that are differentially expressed. Human RAB25 shares 96% aa sequence identity with mouse RAB25. Functionally, RAB25 is involved in the regulation of cell survival. Researchers have shown that RAB25 promotes invasive migration of cells and increases the rates and aggressiveness of breast and ovarian cancers. It is expressed in breast and ovarian tissues.