TIMP3 and renal fibrosis: Consistent with this study, expression of TIMP3 has been positively correlated with aging across different tissues including kidney.26,27 Loss of TIMP3 expression in a mouse model led to tubular and glomerular defects, followed by tubulointerstitial injury and renal fibrosis suggesting a protective role of TIMP3 in kidney.28 Expression of tissue inhibitors of metalloproteases family members including TIMP3 was also observed at advanced stages of replicative senescence in primary fibroblasts29; however, its exact role in senescence is not known.