As shown in Fig. 6a, b, both CD4+ T cells and CD8+ T cells were raised from immunized rats upon challenge infections, compared to non-immunized control rats (Fig. 6; significant differences: CD4+: χ2 = 8.1723, df = 2, P = 0.0163; CD8+: χ2 = 6.4733, df = 2, P = 0.0319). The gene discussed is CD4; the disease is infection.