Microarray analysis of CD19⁺ B cells from 1-month-old ID4^+/−TCL1-tg and ID4^+/+TCL1-tg mice. (A) Heat map of the expression level of probe sets in Affymetrix array with at least a 1.5-fold increase or a 1.5-fold decrease in expression of ID4^+/−TCL1-tg relative to ID4^+/+TCL1-tg mouse B cells obtained from 1-month-old mice. Data are presented from 3 CD19⁺ B-cell samples in each group of 3 mice. Red and green colors indicate high and low expression, respectively. (B) Significantly up- or down-regulated genes in the microarray data were analyzed by the EASE gene ontology annotation tool. The enriched GO terms are listed. (C) Microarray (dark blue bars) and RT-PCR expression (light blue bars) of the 13 potential target genes involved in apoptosis. Fold changes in expression of ID4^+/−TCL1-tg relative to ID4^+/+TCL1-tg mouse B cells are shown graphically and in a table.