The most relevant gene mutation by far involves the BMPR2 gene, which is affected by loss of function mutations in 70–80% of the HPAH and in 10–20% of the IPAH patients.72 Additionally, mutations in genes not part of the canonical TGFβ signalling cascade have also been reported (i.e. CAV1,73TBX4,74EIF2AK4,75 and KCKN376). This evidence concerns the gene BMPR2 and idiopathic pulmonary arterial hypertension.