Septins are members of a conserved family of cytoskeletal GTPases, specifically belonging to the large superclass of P loop GTPases. Septin proteins form homo- and hetero-oligomeric polymers that accumulate into higher-order filaments which may function as dynamic protein scaffolds. Septins play an important role in vesicle trafficking, apoptosis, cytoskeleton remodeling, infection, neurodegeneration, neoplasia and cytokinesis. Septin 11 is mainly present in brain tissue. It has been found to dominantly co-localize with microtubules and Actin stress fibers in HMEC cells and REF52 cells, and to partially co-localize with microtubules and stress fibers in HeLa cells. SEPT11 (the gene encoding Septin 11) is confined to the same tissues as those that express SEPT5, suggesting that SEPT11 and SEPT5 are components of a cell-specific septin complex.