Renalase (RNLS) is a flavoprotein that is secreted by the kidney and circulates in blood from where it can regulate blood pressure, regulate sodium and phosphate excretion and display cardioprotectivity through a mechanism which is not understood to date. RNLS, using FAD as cofactor, can oxidise isomeric forms of beta-NAD(P)H that can arise either by nonspecific reduction of beta-NAD(P)+ or by tautomerisation of beta-NAD(P)H (Milani et al. 2011, Beaupre et al. 2015). These forms are 1,2- and 1,6-dihydroNAD(P) (dh-beta-NAD(P)) and are potent inhibitors of primary metabolism dehydrogenases. RNLS may thus play a role in eliminating these isomeric forms which threaten normal respiratory activity.