IRF4 and neoplasm: As showed in Figure 3E, the percentage of CD11b+Ly6G+Ly6C−/low PMN-MDSCs in the bone marrow and spleen of IRF4 KO tumor-bearing mice were increased significantly (P<0.01), whereas there was no significant change in the percentage of CD11b+Ly6G−Ly6Chigh M-MDSCs (P>0.05).