Clusters of genes categorized by expression patterns during BM regeneration. Transcriptional changes were monitored in transgenic mice for 3 days after GCV treatment. Using an ANOVA parametric test (Welch t test) with P < .05, 150 differentially expressed genes were identified. The vertical axis represents the normalized expression ratios. These genes were clustered in 4 groups based on their expression profiles using a QT clustering method and by functional categories using Gene Ontology database. Some representative categories are shown. VDJ indicates Ig heavy chain gene rearrangement. Unclustered gene profiles (9%) were not represented but were included in the complete gene list available in Table S1.