PP242 reduced the proportion of the leukemic cells attached to primary MSCs in coculture condition. (A). Contour blot depicting different population of attached cells detected by flow cytometry in the coculture setting. Leukemic cells (blue), CD34⁺ AML cells (green), and MSCs (red). Right, microscopic images display these cocultured AML cells and MSCs before and after PP242 treatment. (B) Percentage of AML CD34⁺ progenitor cells attached to the primary AML MSCs in the coculture setting before and after PP242 treatment for 72 hours. In samples from 8 patients depicted by solid lines, the percentage decrease in the attached cell number exceeded the percentage decrease in the total number of cells after the PP242 treatment.