ARG1 and tuberculosis: To further assess the role of macrophage SOCS3 in experimental TB, we analyzed macrophage responses in macrophage-specific SOCS3-deficient (LysMcreSOCS3loxP/loxP) mice (5) and give evidence that in the absence of macrophage SOCS3, IL-6 promotes susceptibility to Mtb infection by the early induction of Arg1 in resident macrophages.