Rapamycin inhibits RFLAT-1 protein expression. (a and b) A CD8+ cell line was stimulated with rIL-2 and cultured with or without rapamycin for 0, 2, 4, and 6 hours. Lysates were subjected to Western blot analysis with anti–RFLAT-1 Ab, anti–phospho-4EBP-1 as control for the effect of rapamycin, and anti-Hsc70. The relative amount of RFLAT-1 protein in each sample was determined as above. Results are representative of two independent experiments. *P < 0.05. Rap, rapamycin.