Moreover, it was observed that targeted disruption of the 5-lipo-oxigenase (5-LO) gene in mice and pharmacologic blockade of 5-LO function in rats reduce chronic hypoxia-associated PAH (Voelkel et al., 1996; Song et al., 2005; Tian et al., 2013). This evidence concerns the gene ALOX5 and pulmonary arterial hypertension.