Expression of BCMA, TACI, and BAFF-R on NHL cells. Tumor cells from patients with B-CLL/SLL (n = 40), follicular (n = 7), DLC (n = 7), mantle cell (n = 7), or marginal zone NHL (n = 8) were stained with biotin-conjugated anti-TACI, anti–BAFF-R, anti-BCMA, or BLyS for 30 minutes on ice, washed, and incubated with PE-streptavidin and CD19-FITC (gray histograms). Histograms correspond to CD19⁺ cells from a representative example of each histologic subtype. Isotype and fluorochrome controls were done for each sample (open histograms).