BLyS-dependent survival is rapamycin sensitive in Pim 2–deficient B cells. CD23⁺ B cells from: (A) wild-type or Pim 1^−/+2^−/+ heterozygotes, (B) Pim 1^−/− 2^−/− double-deficient, or (C) Pim 2 only− deficient (Pim 1^+/− 2^−/−) donors were cultured in CM for 4 days with vehicle, 100 ng/mL rhuBLyS, with or without 50 nM rapamycin (Rapa). Viability was determined daily by trypan blue exclusion. Results are the arithmetic means (±SD) from 3 independent experiments. Statistical comparisons are between BLyS-treated and BLyS and rapamycin-treated B cells (**P < .01; ***P < .001).