Birt–Hogg–Dubé syndrome (BHD) is caused by germline mutations in the FLCN gene and characterized by fibrofolliculomas, lung cysts, spontaneous pneumothorax and renal tumours. The stretch hypothesis for pulmonary cyst formation proposes that cysts in BHD arise from defects in cell–cell adhesion, leading to repeated respiration-induced physical stretch-induced stress and, over time, expansion of alveolar spaces particularly in … Read more…