RAB13 is a small GTPase that regulates intracellular membrane trafficking and plays critical roles in cell migration, tight junction assembly, and vesicle secretion. The protein functions by cycling between inactive GDP-bound and active GTP-bound forms, recruiting downstream effectors to control vesicle formation and fusion 1. RAB13 regulates tight junction assembly by controlling transport of transmembrane proteins like occludin to the plasma membrane and activating PKA signaling pathways 2. The protein is essential for cell migration through multiple mechanisms: it promotes active β1-integrin recycling to focal adhesions via interaction with GGA2 3, and its peripheral translation leads to co-translational association with exchange factor RABIF, which is required for full GTPase activation and efficient migration 1. RAB13 also regulates secretion of small extracellular vesicles (sEVs) in mutant KRAS colorectal cancer cells, serving both as cargo and secretion regulator 4. Clinically, RAB13 overexpression correlates with poor prognosis in multiple cancers and is associated with metastasis-related cell clusters in ovarian cancer 5 6. Additionally, RAB13 influences immune responses by regulating macrophage polarization in sepsis 7.