GEP of the Waldenström clone vs distinct normal B-cell subsets. (A) Heat map of genes with differential expression (false discovery rate q-value <10⁻⁵) between CD22⁺CD25⁻ (n = 9) and CD22^lowCD25⁺ (n = 8) normal bone marrow B-cell subsets. (B) Heat map of 634 genes deregulated (q-value <10⁻⁵) in Waldenström vs CD22⁺CD25⁻ normal B cells and corresponding expression values on CD22^lowCD25⁺. (C) PCA based on the sum of nonoverlapping genes (n = 799) differentially expressed between Waldenström and CD22⁺CD25⁻ normal B cells plus genes differentially expressed between Waldenström and CD22^lowCD25⁺ activated B cells, displayed (along the first principal component) by notched boxes representing 25th and 75th percentile values; the line in the middle and vertical lines correspond to the median value and both the 10th and 90th percentiles, respectively. The color bar depicts normalized intensity values ranging from low (dark blue) to high (dark red) expression levels.