NOS2 and tuberculosis: Thus, the results demonstrated that GK can downregulate the secretion of IL-1β (in Mtb-infected primary macrophages), which has been reported to be involved in TB immunopathology, as well as other critical cytokines including TNF-α and IL-6, and inhibits the production of iNOS and COX2 in Mtb-infected RAW264.7 cells.