Effect of MPA on cyclin D2, cyclin D3, and CDK6 levels. Western blot analysis of cyclin D2 (A), cyclin D3 (B), and CDK6 (C) proteins were performed on extracts of isolated peripheral blood T lymphocytes in the resting state (lane 1), or after stimulation with IL-2/PHA-L for 12, 20, 24, and 36 hours in absence (lanes 2 to 4) or presence (lanes 5 to 7) of 1 μmol/L MPA.