NOS2 and Granuloma: As reported in a murine TB granuloma model of dermal infection in Nos2-deficient C57BL/6 mice, which recapitulates several features of human TB granuloma pathology, such as hypoxia and caseation at the center of granulomas, ARG1 expression in macrophages of hypoxic granulomas plays a beneficial role in controlling bacterial growth and preventing lung pathology (96).