HOXD13 and cancer: Reports have alluded tosPD1 exerting comprehensive T-cell functionrecovery and boosting antitumor immunity through multiple bindinginteractions in the immune checkpoint axis, demonstrating therapeuticeffects that even supersede anti-PD1 antibodies. As a biomarker, serum sPD1 has shown promise in predictingdisease progression, treatment outcomes, and the risk of developingmalignant tumors, making it a hot topic in cancer biomarker research.Therefore, sPD1 quantification from liquid biopsies has an immenseclinical potential.