Transgenic UCH-L1 leads to altered gene expression in GCBs. (A-B) Gene expression profiling was performed using RNA extracted from GCBs from mice of the indicated genotypes (n = 3 each). (A) A heat map represents the relative expression of the 100 most discriminatory genes. (B) The 60 most altered genes (30 up, 30 down; P < .01) are shown with the mean fold-change indicated. (C) The list of genes from panel B were correlated with UCHL1 levels in 215 mature B-cell lymphomas extracted from GSE4475¹⁴  and analyzed using the R2: Genomics Analysis and Visualization Platform (http://r2.amc.nl). The graph represents the Pearson correlation R² value and the corresponding P value for each gene. The hatched area on the left represents a P > .05. Genes with the most significant correlation are indicated in red. (D) IPA was performed using the list of differentially expressed genes (P < .05) from panel A. The graph represents the P values of the top 5 altered biological processes. (E) The expression ratio (mean ± SE) of the list of top upregulated and downregulated genes from panel B in purified mouse light zone (LZ) or dark zone (DZ) cells (GSE38696¹⁷ ) is shown. The P value was calculated with the Student t test. (F) Formalin-fixed paraffin-embedded spleen sections from mice of the indicated genotypes were stained using the TUNEL assay. The graph represents the mean ± SE number of TUNEL-positive cells from 10 randomly selected high-power field (hpf) images from each of 3 mice per genotype (total of 30 hpf per genotype). P values were calculated with the Student t test. (G) Mice of the indicated genotypes (n = 6 each) were immunized with NP-CGG and the level of NP-specific IgG1 was determined by ELISA on the indicated days. *P < .05 (Student t test) for the comparison between IμHABCL6 and any of the other genotypes.