Treatment of mBECs kept in C-SFM with increasing concentrations of cyclosporine (100 to 10,000 ng/ml), caused a concentration-dependent decrease in mBECs [3H]-thymidine incorporation after 48 hours, compared to mBECs treated with tacrolimus (0.1 to 10,000 ng/ml). The results shown are representative of at least three separate experiments (*, P < 0.01; **, P < 0.001; ***, P < 0.0003).