In addition, a better understanding of the pathways regulating macrophage polarization (specifically iNOS and/or Arg1 induction and activity), macrophage trafficking, and the precise effects of iNOS and Arg1 activity on other immune cells following different virus infections will inform the development of therapeutics that target critical effector molecules to promote viral control and limit immunopathology. This evidence concerns the gene NOS2 and viral infectious disease.