To next assess whether His107 methylation of S100A9 is also reduced in vivo during bacterial infection, we utilized a murine model of S. aureus skin infection, in which neutrophils play a primary role in the innate immune response that controls S. aureus infection by forming an abscess to wall off the infection and facilitate bacterial clearance (Kobayashi et al., 2015). Here, S100A9 is linked to bacterial infectious disease.