Hypothesis: epithelial-to-mesenchymal transition is a common cause of chronic allograft failure.

Renal, hepatic, and lung allografts are compromised by aggressively deteriorating function. This chronic process is produced by an overall burden of organ damage, but the pathophysiology remains poorly understood. Rates of chronic rejection in the lung, for example, have not substantially improved over the last decade, despite new immunosuppressive drugs and improvements in surgical procedure. We present a hypothesis that epithelial-to-mesenchymal transition is a common cause of chronic allograft failure. Research in this area may provide insights into chronic rejection of kidney, liver, and lung allografts that impact on future therapeutic strategies.