Survivin is the smallest member of the inhibitor of apoptosis (IAP) protein family, a family of highly conserved cell apoptosis inhibitors characterized by the presence of a zinc-binding fold (the baculoviral IAP repeat), that is comprised of a single N-terminal BIR domain, a long C-terminal α-helix coiled region and a dimeric arrangement. Survivin is a bifunctional protein, apart from its ability to inhibit apoptosis, which also plays an essential role in proper cell division. Survivin is not expressed in most normal and terminally differentiated adult tissues but expressed in fetal tissues, where its expression is cell cycle-regulated and peaks at mitosis.