The core hypotheses of this study are as follows: 1) CD121b+ neutrophils are significantly elevated in patients with septic shock compared to those with sepsis alone, 2) The impact of CD121b+ neutrophils on the progression of sepsis is associated with immune suppression, 3) All-trans retinoic acid (ATRA) could downregulate CD121b expression on neutrophils and can be utilized for alleviating sepsis-induced immunosuppression. Here, IL1R2 is linked to Sepsis.