PDCD1 and neoplasm: For patients who benefited from anti-tumor treatment with anti-PD-1 inhibitors without rejection, two renal transplant recipients were possibly due to the use of low-dose steroid and an mTOR inhibitor, one patient’s advanced urothelial carcinoma regressed after combined treatment with anti-PD-1, anti-VEGF, and chemotherapy without immunosuppressant titration, and one patient had no information in the published article.