CDK9 and acute lymphoblastic leukemia: The gene expression analysis of kinome-specific genes according to the classification of IKZF1 with high, intermediate or low expression in transcriptome data from B-ALL patient samples with Ph-positive (Fig. S6F) subtype showed that the genes PTK2B, CDK9, FGR, CSK, GSK3B, CHEK1 and CSNK2A2, together with IKZF1, exhibited a gradual change in gene expression from the low to high expression classification.