Cytoplasmic tyrosine kinase (CTK) gene expression in AML and normal myeloid cells. RNA isolated from unfractionated AML bone marrow samples or from normal human bone marrow CD34⁺ cells, flow-sorted promyelocytes, and flow-sorted polymorphonuclear leukocytes was hybridized to Affymetrix U133 Plus 2 microarrays. Expression of CTK genes in our discovery set AML samples is rank-ordered from the highest to lowest levels of mean expression (92 of 94 samples had successful array studies performed; the 2 samples without array data are shown as white columns). AML samples are arranged by FAB classification. Expression levels are based on scaled signal intensity values for each probe set (mean value for all probe sets on each array was scaled to a value of 1500 using the MAS 5.0 algorithm), with a value of 0 represented in green and 10 000 or greater as red. Black squares in the right-most column indicate the CTK genes that were resequenced in this study. Below the expression data, the cytogenetic findings and somatic mutation analysis for each sample are shown. Blue boxes indicate the presence of the indicated cytogenetic abnormalities and/or somatic mutations. The bottom-most row indicates the percentage of bone marrow blasts in the AML samples, scaled from 0% (green) to 100% (red); the average blast count for the 94 samples analyzed was 70.5% (range, 30%-100%).