KL and renal fibrosis: Recent studies also show that exogenous klotho decreases high glucose-induced fibronectin and cell hypertrophy via the ERK1/2-p38 kinase signalling pathway to attenuate diabetic nephropathy in vitro [133] and that the administration of klotho protein suppresses renal tubulo-interstitial fibrosis and UUO-induced renal fibrosis, at least partly, by controlling basic fibroblast growth factor-2 signalling in vivo [134].