NOS2 and infection: Immediately following infection, monocyte and macrophage populations in the liver have a classic inflammatory M1 phenotype (CD80+CD206-; inducible nitric oxide synthase [iNOS]+), but these inflammatory cells begin to transition to anti-inflammatory, reparative M2-like phenotype (CD80−CD206+; arginase+) 2–3 weeks post-infection (Figures 3H–3K; Figure S1).