There is growing evidence that MRP4 could be a potential target for cardiovascular disease (29): MRP4 inhibition was able to prevent human coronary and pulmonary arteries smooth muscle cell proliferation, as well as pulmonary hypertension in mice (30); moreover, an upregulation of MRP4 was found in pathological conditions, like in pulmonary arteries from patients with pulmonary arterial hypertension or in mice exposed to hypoxic conditions. This evidence concerns the gene ABCC4 and pulmonary arterial hypertension.