S100A9 and allergic asthma: Flow cytometry results showed that the proportion of M1 (CD86+) and M2 (CD206+) macrophages was decreased in OVA-induced allergic asthma mice with 3-BP intervention, whereas they increased in OVA-sensitized and challenged mice with S100A9 overexpression (p < 0.01) (Figs. 7A, 7B).