The generation of immunity to M. tuberculosis through the generation of BCG-induced Trm cells has been reported; since the BCG vaccine protects infants but confers poor protection against pulmonary TB in adolescents and adults, assays using an intradermal murine BCG vaccination model have been developed, inducing a population of antigen-specific CD4+ T cells within the lung parenchyma that persists for >12 months post-vaccination [126]. This evidence concerns the gene CD4 and pulmonary tuberculosis.