ATP6AP2 and essential hypertension: Although the soluble PRR (sPRR) is also augmented and detected during experimental models of hypertension [10,44,45,46] and correlates with renal function in essential hypertensives [47], other studies suggested that serum sPRR concentration is independent of blood pressure levels and of renin and prorenin concentrations in patients with very diverse degrees of RAS activity and also in patients with diabetes [48].