BCMA and TACI expression by flow cytometry. Freshly purified CD138⁺ cells were first incubated with anti-BCMA or anti-TACI followed by staining with PE-conjugated goat anti–rat IgG. (A) Representative histograms showing BCMA and TACI expression on primary CD138⁺ cells. BCMA histograms: (i) t(4;14); (ii) t(11;14). TACI histograms: (iii) t(14;16); (iv) cyclin D1⁺ with no IgH/TC. (B) Levels of BCMA and TACI expression according to D-type cyclin class. Median values are indicated (n = 14 in each group, 8 cyclin D2⁺ with circulating plasma cells, and 2 cyclin D1⁺ with circulating plasma cells).