Therapeutic administration of PGZ to mice also resulted in the down-regulation of M1 macrophage gene expression (Figure 2C) and increased M2a macrophage gene expression of Mrc1 in the lungs of mice (Figure 2D) on Day 6 post-infection, although the increased trend in the level of Arg1 mRNA did not achieve statistical significance. Here, MRC1 is linked to infection.