Rapamycin decreases DNTs. CBA-lpr^cg mice were randomized to treatment with rapamycin 5 mg/kg/day versus vehicle control. Retro-orbital bleeds were performed every 2 weeks to assess absolute DNTs/mm³. Treated mice showed a statistically significant decrease in absolute DNTs compared with control by 4 weeks of treatment. No statistical difference existed between groups at initiation of treatment. Bars represent mean absolute DNT count from mice at each time point; error bars represent SEM. Normal mouse absolute DNT count range, 30 to 150/mm³.^9,18