PDCD1 and Sepsis: There is an interest in novel therapeutic approaches to stimulate the immune function in patients with sepsis; these include interleukin-7 (IL-7), granulocyte–macrophage colony-stimulating factor (GM-CSF) as well as antibodies against programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1).