IFNG and infection: The data reported in this paper suggest that IFN-γ+ T-cell responses to PPE44 may be associated to immune protection also in human M. tuberculosis infection: indeed, IFN-γ+ T-cells specific for the immunodominant PPE44 peptide p1L were detectable in all individuals whose immune system is likely to have determined the containment of infection and prevented progression to active TB disease (PPD+ healthy subjects), as well as in a proportion of BCG-vaccinated subjects.