We saw reduced frequency of CD3+CD4+ T cells (B6 = 80.33 ± 4.07 vs. pMT-10 = 73.09 ± 4.52, P ≤ 0.01) and CD4+ T cells capable of producing IFN-γ in response to ESAT61–20 (B6 = 3.47 ± 0.53 vs. pMT-10 = 2.9 ± 0.74, not significant) at day 65 after infection. The gene discussed is CD4; the disease is infection.