CD38-expression levels are differently regulated in B-CLL cells and T cells. CD38-expression levels in B-CLL cells were plotted against those detected in T cells. Analysis from female (n = 84; A) and male patients (n = 115; B) revealed a very low degree of correlation as indicated by the correlation coefficient presented on top of the graphs. The fitted regression lines are plotted as solid lines. The dotted lines mark the cutoff values for definition of high-risk groups (ie, expression of CD38 in at least 30% of B-CLL cells and 50% of T cells).