Host response: Inflammation promotes TB growth Nature Microbiology, Published online: 27 June 2017; doi:10.1038/nmicrobiol.2017.102 Nitric oxide synthase has long been associated with control of Mycobacterium tuberculosis infection. However, new work reveals that instead of directing an antibacterial killing response, nitric oxide is critical for restraining granulocytic inflammation, which can provide a nutrient-rich niche for increased bacterial growth.