NPPA and chronic kidney disease: Two of these proprotein convertases have been previously associated with kidney disease: specifically, in the kidney, a high-salt diet induces the PCSK6-corin-ANP-AQP2/β-ENaC pathway suggesting the importance of PCSK6 in renal failure [53], whereas PCSK7 is linked to end-stage renal disease (ESRD) [54].