Validation of selected microarray results by Q-PCR. Changes in target gene expression during ex vivo erythropoiesis are depicted. The vertical axis represents the target gene expression normalized to PABPC1 expression and relative to the UR/FL calibrator (as described in “Quantitative real-time polymerase chain reaction”). Black lines indicate average expression in control erythroblasts (n = 4); gray lines indicate average expression in In(Lu) erythroblasts (n = 4).