Flow cytometry detected a significantly higher proportion of peripheral blood CD4+CD25+CD127low Tregs in the TB group than in the control group (9.14% ± 2.66% vs. 6.39% ± 1.73%; t = 4.067, P < 0.001), and a higher proportion of peripheral blood CD4+CD25+CD127low Tregs among active pulmonary TB patients with a positive anti-M. The gene discussed is CD4; the disease is tuberculosis.