Effects of R221 treatment on monocyte/macrophage populations in NSG and C57BL/6 mice. (A) Representative flow cytometry analysis showing the percentage of granulocytes (CD11b⁺F4/80⁻), monocytes (CD11b⁺F4/80^int), and monocyte-derived macrophages (CD11b^lowF4/80^hi) gated on viable CD45⁺ cells isolated from the spleen of R221- or vehicle control–treated NSG mice (n = 7 per group) xenografted with RS9737 cells. The box plot shows the absolute number of granulocytes (Gran), monocytes (Mo), and macrophages (Mφ) in the spleen of vehicle control– and R221-treated NSG mice. (B) Flow cytometry dot plots and box plot showing the percentage (left) and the absolute number (right) of Gran, Mo, and Mφ in the spleen of R221- or vehicle control–treated C57/BL6 mice. (C) Flow cytometry dot plots and box plot showing the percentage (left) and the absolute number (right) of monocyte-derived Mφ (CD11b⁺F4/80^int) and tissue-resident Mφ (CD11b⁺F4/80^hi) in the PC of R221 and vehicle control C57/BL6 mice. Cell populations were defined as described in Hanna et al⁴⁴ Statistical analysis was done using the t test or Mann-Whitney test, as appropriate.