Birt-Hogg-Dubé (BHD) is a rare autosomal dominant genodermatosis, characterized by cutaneous hamartomas, pulmonary cysts, spontaneous pneumothorax and kidney tumours. BHD is caused by mutation in the gene which codes for folliculin (FLCN). FLCN is part of the mTOR-AMPK signal transduction pathway. Genetic testing of patients is now possible. Furthermore, understanding of the biology and mechanisms behind BHD-associated disease provides an opportunity for development of new treatment options.