Accumulation of IMCs in skin of S100A9Tg mice. (A) Amount of S100A9 protein in various organs of WT and S100A9Tg mice. Typical example of Western blotting of 30 µg tissue protein is shown. (B) S100A9 protein in skin samples from WT and S100A9Tg mice treated with TPA or vehicle (acetone). Each lane represents an individual mouse. (C) Representative IHC images showing the presence of Gr-1⁺ cells in skin. Bar, 100 µm. (D) The number of Gr-1⁺ cells per square millimeter of skin tissue. (E) Phenotype of myeloid cells accumulated in skin of TPA-treated mice. Representative flow cytometry plots are shown with numbers indicating percentage of gated cells. Bar graph on the right illustrates the proportions of cell populations. (F and G) The number of F4/80⁺ (F) and CD11c⁺ (G) cells in skin of mice treated with TPA or acetone as indicated. (H and I) Proportion (left) and absolute number (right) of Gr-1⁺CD11b⁺ (H) and Ly6C/Ly6G ratio within the population of CD11b⁺ cells (I) in BM of TPA-treated mice. (D–I) Each group included four mice. Mean and SD are shown. *, P < 0.05; **, P < 0.01.