FLCN and Fibrofolliculoma: The FLCN gene is considered to function as a tumor suppressor gene, because somatic mutations in the remaining wild-type FLCN genes or loss of heterozygosity were identified in BHDS-associated renal tumors9, whereas FLCN haploinsufficiency appears to be sufficient to initiate uncontrolled cell growth of benign tumors leading to fibrofolliculomas in the skin10.