By deleting PtpA from Mycobacterium bovis bacillus Calmette‐Guérin (BCG), these studies showed that the protein suppresses the production of TNF, IL‐1β, and IL‐12 by macrophages both in vitro as well as in mice, which also harbored fewer bacteria in the lungs compared to mice infected with wild‐type BCG.29, 30 This observation contrasts with the deletion of PtpA in M. tuberculosis that, as discussed earlier, does not attenuate the pathogen during infection in vivo. The gene discussed is TNF; the disease is infection.