In previous studies we noted that HIV-seronegative adults with prior extrapulmonary tuberculosis had lower levels of CD4+ lymphocytes, unstimulated cytokine production, and tumor necrosis factor (TNF)-α production in response to lipopolysaccharide (LPS) or LPS + interferon (IFN)-γ than persons with prior pulmonary tuberculosis or latent M. tuberculosis infection[6,7]. This evidence concerns the gene CD4 and extrapulmonary tuberculosis.