Moreover, that the expression of 5-LOX was increased in the neointimal cells of the pulmonary artery in BMPR2+/− rats or in patients with PAH with BMPR2 variants [67], indicating that LTB4 is an important mediator that drive the progression of PH as a factor of a ‘two hit’ model of PAH. This evidence concerns the gene ALOX5 and pulmonary arterial hypertension.