ALOX15B and pulmonary arterial hypertension: Lipoxygenases (LOXs) are non‐haeme iron dioxygenases that stereospecifically introduce molecular oxygen into polyunsaturated fatty acids, resulting in the formation of hydroperoxyeicosatetraenoic acids, which are subsequently converted to HETEs.32 Two 15‐LOXs, including 15‐LOX1 and 15‐LOX2, have been shown to be widely expressed.33 Additionally, 15‐LOX1 has been observed as an important factor in the pathogenesis of atherosclerosis and pulmonary artery hypertension, and up‐regulated in pulmonary artery adventitial fibroblasts under hypoxia.