A central role for IFN-γ in the immune response to TB is well-established (31–34), and our findings suggest that it may contribute to bacterial clearance from the site of in vivo infection and control of mycobacterial growth following in vitro infection, although it is yet to be determined which cell populations are contributing to IFN-γ secretion, and cell phenotyping would be of interest. The gene discussed is IFNG; the disease is tuberculosis.