PDCD1 and Sepsis: This review seeks to examine and consolidate the existing understanding of lymphocyte apoptosis, the involvement of the programmed cell death protein 1/programmed death ligand 1 (PD-1/PD-L1) axis, and interleukin-7 (IL-7) in sepsis, with an emphasis on their underlying processes, clinical significance, and potential for future immunomodulatory treatments.