Meanwhile as compared with the control group (sham+SA), the alveolar lavage fluid and serum samples of mice in the CLP+SA group revealed lower levels of proinflammatory cytokines or chemokines (including TNF-α, IL-1β, IL-17A, IL-6, and CCL-4) and higher levels of anti-inflammatory cytokines (IL-10), indicating that the sepsis-induced secondary S. aureus pneumonia mouse model presented an immunosuppressive state (Figure 2(f)). Here, CCL4 is linked to Sepsis.