Delivery of subunit TB vaccines to the respiratory tract elicited high numbers of Ag-specific CD4 and CD8 T cells in the airway lumen that were capable of IFN-γ production and cytolytic activities, while parenteral immunization failed to induce any T cell response in the airway lumen but rather led to activation of T cells in the spleen [32]. The gene discussed is CD8A; the disease is tuberculosis.