Moreover, the bacterial burdens in the air pouches at 48 h post-infection were significantly increased, compared with 24 h post-infection, regardless of whether they were GAS-infected WT, IL-33-KO, or ST2-KO mice, and the pattern of bacterial burdens among different groups were similar to that of 24 h post-infection (Figure 3a). The gene discussed is IL33; the disease is infection.