FLCN and supranuclear palsy, progressive, 1: The folliculin (FLCN) gene, a tumor suppressor gene localized in the short arm of the chromosome (17p11.2), was first identified in 2001 and reported to be associated with PSP, fibrofolliculoma, pulmonary cyst, and Birt–Hogg–Dubé Syndrome‐associated kidney cysts (Graham et al., 2005).