Individuals with pneumothoraces are frequently divided into young patients with so-called primary spontaneous pneumothorax and older patients with lung disease causing secondary pneumothoraces. In truth, the younger patients may also have underlying lung disease either acquired through smoking, particularly cannabis, or inherited. Ten percent of individuals presenting with apparently primary pneumothoraces will have a family history of pneumothorax, indicating a large heritable component (1). The most common genetic diagnosis in patients with familial pneumothoraces is Birt-Hogg-Dubé syndrome (BHD), an autosomal dominant condition caused by mutations of the FLCN gene encoding the protein folliculin. Two articles in this edition of Thorax address different aspect of BHD biology with potential implications for the diagnosis and management of these patients