Pharmacological block of p38 MAPK partially inhibits Dex-dependent cell death in CEM and RPMI clones converted to Dex-sensitive by AZA treatment. CEM IV B9 and RPMI II E6 cells were diluted to a starting density of 1×105 viable cells/ml, pre-treated for 1 hr with ethanol/DMSO vehicle (control) or 1 μg/ml p38 inhibitor SB203580 (SB) for CEM cells or 2 μg/ml SB for RPMI cells, and subsequently exposed to 1 μM Dex alone (Dex) or the combination of SB plus Dex (SB + Dex) for an additional 48 hours. Viable cells were counted using an automated cell counter. Depicted are the average results and standard deviations from 3 independent experiments each consisting of triplicate replicates for each treatment. Paired t-tests were performed on viable cell numbers and culture viability for (Dex) vs. (SB + Dex). n = 3.