This long-term experimental animal study of CsA-nephrotoxicity demonstrates a significant protective action of an MR antagonist on tissue injury (reduced renal fibrosis, interstitial expansion, and loss of tubular mass), GFR, BP and the ability to thrive, and suggests that MR antagonists should be tested for their renoprotective actions in clinical settings. Here, NR3C2 is linked to renal fibrosis.