Swirski et al. presented that inflammatory monocyte (Ly6Chigh subset) are more enriched in MPO activity than nonclassical monocytes (Ly6Clow subset) and this MPO-rich inflammatory monocytes (Ly6Chigh subset) promote inflammation and tissue destruction through the release of proteases and inflammatory cytokines such as TNF-α in various inflammatory settings including infection and injury [57]. This evidence concerns the gene MPO and infection.