Time-dependent changes in gene functions triggered by BCR stimulation in immature and mature B cells. The most significant gene ontology categories for the genes discriminating between BCR-triggered (BCR) and control (ctrl) immature and mature B cells at 2 h are listed. Genes were identified by one-way ANOVA (P < 0.01). The P-value that is shown with each functional category indicates its statistical enrichment compared to the whole set of genes that were assayed with the microarrays. The significance of each category was evaluated using the modified Fisher's exact test employed by the DAVID functional annotation tool . The most significantly enriched functional categories in mature B cells have been highlighted in color to facilitate their viewing.