Quantitative real-time RT-PCR (LightCycler) validation of 16 genes selected by microarray analysis on resistant B-CLL samples. The relative RT-PCR and microarray expression levels of the same resistant B-CLL samples are shown; fold change (FC) ratios for microarray analysis and the ratios for RT-PCR were calculated by taking into account the expression levels of GAPDH. The microarray data are shown as shaded columns and RT-PCR data as light columns. Down-regulation is shown in green and up-regulation in red. Note that one gene (APR peptide, access number D90070) was found to be up-regulated by microarray analysis and down-regulated by RT-PCR. Note that APR transcript (access number D90070) was not validated and that the RT-PCR result for one selected gene (HLA-DQA1 MHC protein, access number M34996) is not given.