REN and chronic kidney disease: We hypothesized that the oral supplementation with the BHB precursor 1,3-butanediol in addition to inhibitors of the renin-angiotensin system (RAS) and sodium-glucose transporter 2 (SGLT2) would be superior to dual RAS/SGLT2 blockade alone in attenuating the loss of GFR in Col4a3-deficient mice with Alport nephropathy, a spontaneous model of progressive CKD.