Although T-SPOT.TB assay was more sensitive than TST, the positive rate of T-SPOT.TB assay was decreased to only 44.4% in HIV patients with CD4+ T cells <200/μl, comparing 74.2% and 67.9% in HIV patients with CD4+ T cells >500/μl and 200–500/μl, respectively. This evidence concerns the gene CD4 and tuberculosis.