Folliculin protein (579 aa, ~64 kDa) is encoded by the human FLCN gene. This protein is purported to play a role in tumor suppresion, but an exact function has yet to be identified. Mutations and truncations in the protein have been implicated in the pathogenesis of fibrofolliculoma formation, Birt-Hogg-Dube syndrome, and colorectal tumorigenesis. [ ]