CD11b expression in ALL blasts under therapy: modulation vs selection. Comparison of absolute counts of CD11b⁺ blasts (the numbers of blasts/μL in the dot plots) at diagnosis and day 15. In the dot plots only CD19⁺ cells are depicted. Leukemic cells are shown as black dots and normal B cells as gray dots. Quantification of the CD11b⁺ leukemic cells (gated by solid-line circles) shows 2 cases of the therapy-induced CD11b up-regulation (left and middle). The right plots indicate selection of CD11b⁺ cells from initial 2 CD11b⁺ and CD11b⁻ subpopulations of leukemic cells.