While a large majority of cases of hereditary PAH are associated with mutations in the bone morphogenic protein receptor type II (BMPR2), of particular interest in this review are several recent studies implicating mutations in genes encoding for two different potassium channels—potassium channel subfamily K member 3 (KCNK3) and ATP-binding cassette subfamily C member 8 (ABCC8)—as PAH-predisposing genes [11,12]. This evidence concerns the gene KCNA3 and pulmonary arterial hypertension.