More importantly, S100A9 were confirmed to enhance both the number and suppressive function of MDSCs in several pre-clinical studies, inhibition of which reportedly restored CD8+ T cell-mediated anti-tumor responses in lymphoma and prevented repressor activity of MDSCs in sepsis, prompting us to investigate the relationship between S100A9+ monocytes and MDSCs [29, 62]. Here, S100A9 is linked to Sepsis.