Validation of microarray data by real-time PCR. Real-time PCR was used to validate results from microarray. Genes were sorted according to the highest expression by (A) classical (green hatched bars), (B) intermediate (purple bars), and (C) nonclassical subsets (red striped bars). Real-time PCR results are shown in darker shades and expressed as mean ± SEM of 3 to 7 independent donors. Microarray results are in lighter shades and expressed as median ± SD of 4 independent donors.