In contrast, numerous studies have demonstrated that T cells from infants vaccinated with the live BCG vaccine, as well as infants and young children with asymptomatic Mtb infection and those ill with TB, are capable of mounting Mtb-specific CD4+ and CD8+ T-cell responses characterized by robust IFN-γ production [25,26,27,28,29,30,31,32]. This evidence concerns the gene CD4 and tuberculosis.