SEPTIN11 is a cytoskeletal GTPase that functions as a filament-forming protein involved in multiple cellular processes. Mechanistically, SEPTIN11 forms heteropolymeric complexes with other septins (SEPT2, SEPT4, SEPT7) and localizes to sites of active membrane dynamics 1. The protein plays critical roles in cytokinesis, as evidenced by its essential function during polar body extrusion in oocytes where maternal SEPTIN11 is required for septin-complex assembly at the polar body extrusion site 2. SEPTIN11 also regulates cytoskeletal dynamics through RhoA activation; in hepatocellular carcinoma cells, SEPTIN11 promotes cell motility by facilitating RhoA-GEF-H1 binding, leading to actin rearrangement and altered cell adhesion via ROCK1/cofilin and FAK/paxillin pathways 3. Additionally, SEPTIN11 is required for efficient FcγR-mediated phagocytosis in macrophages and neutrophils, operating downstream of actin recruitment 4. In adipocytes, SEPTIN11 associates with caveolin-1 and FABP5 at lipid droplets, regulating lipid storage and insulin signaling 5. Clinically, reduced SEPTIN11 expression in endometrial epithelial cells impairs cell adhesion and endometrial receptivity 3, while elevated expression associates with poor prognosis in hepatocellular carcinoma 6. SEPTIN11 is broadly expressed across tissues, with particular enrichment in brain 7.