The importance of Treg cells in tuberculosis has been demonstrated (20, 21), although their specific role during tuberculosis is not well understood but may involve restricting the “strong” Th1 responses induced by microbial antigens and to prevent excessive inflammation and tissue damage (22) and enhanced activation of CD4+ CD25+ Treg cells may negatively modulate anti-TB immune responses (23). This evidence concerns the gene CD4 and tuberculosis.