Figure 1. IL-4 induces M2 macrophage polarization in vitro. IL-4 was used to induce M2 macrophages from cultured macrophages derived from bone marrow in culture. (A-C) mRNA levels of Arginase 1 (Arg-1; A), Ym-1 (B) and Fizz-1 (C) by RT-qPCR. (D) Arginase assay. (E) Flow cytometry for CD206 in CTL (-) and IL-4-treated macrophages. **p<0.01. *p<0.05. N=5.