However, circulating CCL2 is elevated in PAH patients (Soon et al., 2010; Sanchez et al., 2007; Itoh et al., 2006), so BMPR-II dysfunction, leading to dysregulation of other pathways mediating CCL2 production, may still be involved in the pathology of PAH. This evidence concerns the gene BMPR2 and pulmonary arterial hypertension.