Drug application to Cbl^Q367PCMML cells. (A) Experimental procedure of drug application. BM cells of control or Cbl^Q367P mice (Ly5.2⁺) were transplanted into irradiated syngeneic mice (Ly5.1⁺), and, after confirming the development of CMML, recipient mice were subjected to drug administration, and the Ly5.2⁺ cells were analyzed. (B) Left two panels: Changes in the numbers of total and Mac1⁺ Ly5.2⁺ cells in the PB of drug-treated recipients during the observation period. Right panels: hemoglobin (Hb) concentrations and platelet (Plt) count at 4 weeks after treatment. (C) Analyses of the spleen. Left two panels: Representative macroscopic appearances and weights of the spleens of drug-treated recipients. Right two panels: Mac1⁺ and B220⁺ cell numbers of Cbl^Q367P+Vehicle and Cbl^Q367P+Comb recipients. (D) Analyses of the BM. Upper panels: Representative photos taken with a phase-contrast microscope and total colony numbers (diameter, >500 µm) of drug-treated recipients. Scale bar: 500 μm. Lower panels: LSK cell numbers and percentages of Annexin V⁺ cells in the LT-HSC, ST-HSC and MPP fractions of Cbl^Q367P+Vehicle and Cbl^Q367P+Comb recipients. **P < .01, *P < .05. ns, not significant.