There are also potential implications related to BMPR2 gene mutation or subsequent downstream pathway dysfunction and altered iron handling in PAH, as BMPR2/SMAD pathways, amongst other functions, are also involved in regulation of iron homeostasis, facilitated through the control of hepcidin production (Figure 2) (Finberg, 2013). The gene discussed is HAMP; the disease is pulmonary arterial hypertension.