S100A8 and bacterial arthritis: Staphylococcus aureus lipoproteins are the most potent bacterial component causing joint inflammation and bone damage in septic arthritis (Mohammad et al., 2019) Here, we i.a injected the mouse knees with synthetic lipopeptides (Pam2CSK4 and Pam3CSK4) to observe whether lipopeptides upregulates S100a8/a9.