Although no studies to date have indicated a direct relationship between PD-L1 and the growth of parathyroid adenomas, based on immunological mechanisms, we hypothesize that PD-1 inhibitors may block the PD-1/PD-L1 signaling pathway, thereby alleviating the immunosuppressive state within the tumor microenvironment, leading to abnormal proliferation of primary parathyroid adenoma cells and subsequent hyperparathyroidism (13). The gene discussed is CD274; the disease is hyperparathyroidism.