FLCN and cystic disease of lung: Germline mutations of the BHD gene, which is on chromosome 17p11.2 and was cloned in 2002 [13], lead to an autosomal dominant disease associated with fibrofolliculomas (benign skin tumors), cystic lung disease, which can result in spontaneous pneumothorax (lung collapse), and renal cell carcinomas (RCC), which are most often of the chromophobe subtype.