Differences between cyclosporin A and tacrolimus in organ transplantation.

In addition to their effect on the TCR-mediated signal transduction, both CyA and tacrolimus affect a wide variety of other biological processes, including induction of cell exocytosis and side effects. Although calcineurin has been implicated directly or indirectly in many of these processes, it seems plausible that the mechanisms by which these two drugs exert their full immunosuppressive activity are not necessarily the same. The cellular and molecular networks under differential immunosuppression by these two drugs remain to be explored. However, considering that investigations in this area are still ongoing, the answers will undoubtedly be available in the not too distant future.