DNA microarray analysis identified 181 genes that were significantly different in sort-purified follicular (FO) vs. marginal zone (MZ) B cells from MD4 transgenic mice (B6 background). The identified transcripts have a fold change > 2 and a p value < 0.02 by T-test. The differentially expressed genes were grouped into various functional categories (A) Motility/Adhesion, (B) Immune Response, (C) Apoptosis, and (D) Proliferation. Shown are normalized expression values greater than (yellow), near (black), or less than (blue) the mean of that gene. Each column represents one independent sample of sort-purified FO or MZ B cells. Genes or transcripts are represented in rows. Clustering of the genes is unsupervised.