Consistently, a clinical trial indicated that a subset of IPAH patients who have loss-of-function genetic polymorphisms in SIRT3 (sirtuin 3) and UCP2 (uncoupling protein 2) do not respond to dichloroacetate (DCA, a PDH kinase inhibitor), highlighting the involvement of SIRT3 in mitochondrial dysfunction in PH [126]. Here, UCP2 is linked to idiopathic pulmonary arterial hypertension.