Validation of Genechip results by real-time PCR. For selected characteristic genes with altered expression by gene chip analysis an independent analysis using quantitative Taqman PCR was performed. Bars on the right of the axis represent upmodulated genes in CD34 cells after IFN-γ treatment. Bars on the left side of the axis represent downmodulated genes. ▨ indicates oligoarray results; and ▪, the corresponding real-time PCR results. Mean values of 2 independent experiments performed in duplicate. (A) Selected genes involved in apoptosis and cell death. (B) Selected genes coding for cytokines/chemokine receptors. (C) Miscellaneous genes. Error bars indicate SDs.