The upregulation of the inhibitory immune checkpoint molecules PD-1 and its corresponding ligand PD-L1 characterized immunosuppression 40, and previous studies have demonstrated that the immunomodulation strategy, via administrating anti-PD-1/PD-L1 antibodies such as nivolumab and BMS-936559, could improve survival by restoring immune cell function in sepsis models 40-42. This evidence concerns the gene PDCD1 and Sepsis.