RAB11B is a small GTPase belonging to the RAS oncogene family that regulates intracellular membrane trafficking and vesicle transport 1. RAB11B localizes to a distinct apical pericentrisomal vesicular compartment that differs from RAB11A and is less dependent on microtubules for positioning 1. The protein plays critical roles in viral pathogenesis, particularly during enterovirus A71 infection, where it facilitates virus morphogenesis by recruiting chaperone proteins including CCT8 to support provirion maturation and VP0 cleavage 2. In cancer biology, RAB11B demonstrates context-dependent functions - it promotes breast cancer brain metastasis by controlling integrin β1 surface expression through recycling mechanisms, enabling efficient interaction with brain extracellular matrix and mechanotransduction signaling 3. However, RAB11B expression appears to be tumor-suppressive in other cancers, as its antisense RNA RAB11B-AS1 is downregulated in hepatocellular carcinoma and osteosarcoma, where reduced expression correlates with poor prognosis 45. Additionally, RAB11B contributes to immune regulation through the TNFα/ICAM-1/Rab11b axis, mediating neutrophil aggregation and extracellular vesicle release in mesenchymal stromal cell therapy for systemic lupus erythematosus 6. These findings highlight RAB11B's diverse roles in cellular trafficking, viral infection, cancer progression, and immune modulation.