Most recently, further rare mutations in genes linked to the BMP signaling pathway have been identified such as KCNA3 or KCNA5 mutations in IPAH [8–11], CAV-1 [12], BMP9/GDF2 in HPAH [13–15], EIF2AK4 in patients with pulmonary veno-occlusive disease [16, 17]. This evidence concerns the gene GDF2 and pulmonary venoocclusive disease.