TNF and infection: It is interesting to note that a similar population of non-culturable bacteria could also be isolated when MTB was grown in macrophages [25] Evidently, the stable CFUs in organs at 60 days post infection are controlled in an immune dependent fashion as with low dose aerosol infection since immune suppression by AG or anti-TNFα antibodies resulted in significant increase of CFU levels in lungs after 20–30 days of drug administration.