Volcano plots representing the relationship between fold change and statistical significance. On the x-axis are represented the log 2 fold change between the two groups (macrophages and monocytes). The vertical axis represents the log-Odds (B-Statistic) computed in Limma. Each gene is represented by a point and an up- and down-regulated gene appears symmetric. B statistics represents the log-odds that the gene is differentially expressed between the two groups. A low B-value indicates little evidence of differential expression. Highlighted genes represent the top 20 significant genes identified on Affymetrix (a), Illumina (b) and RNG-86 (c) platforms.