The results showed that infection of macrophages with the ∆stir-2 mutant increased the expression of IL-6 (Figure 4A), IL-1β (Figure 4B), and TNF-α (Figure 4C) at 18, 24, and 48 hpi compared with macrophages infected with the wild-type SC09 strain or the ∆stir-2 + pSTIR-2 mutant strain. The gene discussed is IL6; the disease is infection.