Percentages of CD38⁺CD19⁺ cells among the modified Rai stages.

Note that there was a clear distinction between the cases that had more than 30% CD38⁺ B-CLL cells and those expressing low numbers (< 30%) of CD38⁺ B-CLL cells within each modified Rai stage (low, intermediate, and high). These comparisons were statistically significant (P = .0002; Mann-Whitney test).