Rapamycin and chronic kidney disease: beyond the inhibition of inflammation.

Rapamycin, a potent inhibitor of the mammalian target of rapamycin (mTOR) protein kinase, is a well-known immunosuppressive agent. In this issue, Wu and colleagues report that rapamycin significantly attenuates renal interstitial fibrosis in obstructive nephropathy. Besides its inhibition of renal inflammation, rapamycin is able to block tubular epithelial-mesenchymal transition, thereby shedding new light on the mechanism of its antifibrotic actions.