NOS2 and bacterial infectious disease: We did this by focusing on the colonization and replication of the pathogens, the microscopic lesion development, and the cytokine mRNA expression of the host, specifically the potent antiviral factors IFNα [44] and IFNλ [32,45], as well as inducible nitric oxide synthase (iNOS), known to be induced by viral and bacterial infections [46,47].