Using a cohort of 2572 cases from the PAH Biobank, the authors identified numerous deleterious germline and somatic variants of TET2. The authors reported that inherited and acquired abnormalities in TET2 occur in 0.39% of PAH cases, with 75% predicted germline mutations and 25% predicted somatic mutations in TET2 [33]. Here, TET2 is linked to pulmonary arterial hypertension.