Septin-6 is a filament-forming GTPase that participates in cytokenisis and is necessary for the normal organization of the actin cytoskeleton. It is widely expressed in tissues and is found in the cytoplasm and in the spindle during metaphase. Four isoforms of Septin-6 have been described. As a protein family Septins were first characterized as regulators of cytokinesis. These proteins were later shown to have a broader role in microtubule-dependent processes, such as karyokinesis, exocytosis, and maintenance of cell shape. Several septin family members are known to colocalize or interact with the microtubule cytoskeleton and are believed to play a role in regulating microtubule dynamics through interactions with microtubule-associated proteins (MAPs).