Flow cytometry (FACS) analysis of circulating cells in HCL patient no. 30. At 3 different time points, pretreatment (A and B), cycle 1 day 8 (C and D), and cycle 2 day 145 (E and F), data from 2-color analyses are shown to identify CD25⁺/CD19⁺ cells (A, C, and E) or CD11c⁺/CD103⁺ cells (B, D, and F). Perpendicular lines were drawn to differentiate malignant (upper-right quadrants) from nonmalignant cells. Horizontal lines in (B), (D), and (F) are drawn above nonmalignant cells that are dimly positive for CD11c.