HIF1A and idiopathic pulmonary arterial hypertension: In rats with IPAH, chromosomal abnormalities on chromosome 1 result in reduced expression of electron transport chain complexes I, III, SOD2, and COX4 in the mitochondria of PASMCs, lowers overall ROS production, promoting the nuclear translocation of HIF-1α, which subsequently decreases Kv1.5 expression.134 However, the decreased expression of Kv1.5 in PASMCs of hypoxic rats inhibited Caspase-3, thereby preventing apoptosis.135 Moreover, hypoxia-induced dephosphorylation of FUNDC1 in PASMCs strengthened its interaction with LC3B-II, resulting in enhanced mitochondrial autophagy.