¹Division of Cellular and Molecular Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.

Correspondence: Y Liu, Department of Pathology, University of Pittsburgh, S-405 Biomedical Science Tower, 200 Lothrop Street, Pittsburgh, Pennsylvania 15261, USA. E-mail: liuy@upmc.edu.

Abstract

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.