Stathmin (STMN1) is a ubiquitous cytosolic phosphoprotein which belongs to the Stathmin family. STMN1 is expressed in many tissues, with the highest expression in the brain, spinal cord, and cerebellum. It can also be expressed in the colon, ovary, placenta, uterus, and trachea. STMN1 participates in the regulation of the microtubule filament structure by destabilizing microtubules. STMN1 promotes the disassembly of microtubules and prevents assembly. STMN1 is involved in the control of the learned and innate fear. STMN1 is an intracellular relay integrating regulatory signals of the cellular environment and as an Oncoprotein in regulation of the cell cycle. Phosphorylation at Ser-16 may be required for axon formation during neurogenesis. Mutation in STMN1 effects cell homeostasis that may lead to tumorigenicity.