Relative mRNA expression of genes differentially expressed at relapse after exposure to vorinostat. Quantitative RT-PCR validation of selected targets on 3 primary patient samples and Reh, RS4:11, and MV4:11 cell lines is shown. The x-axis represents the vorinostat concentration. The y-axis represents normalized ΔCT values (CT of gene of interest − CT of the housekeeping gene). CT indicates threshold cycles for amplification. Each experiment was performed in triplicate. Mean expression is indicated by the horizontal bars. P values correspond to Wilcoxon signed-rank test comparing the expression levels before and after treatment.