CD274 and systemic lupus erythematosus: Considering the immunosuppressive feature of PD-L1 and the fact that the frequency of PD-L1-expressing neutrophils is associated with disease activity and severity in SLE, our research suggests that the increased frequency of PD-L1-expressing neutrophils may serve as a negative feedback mechanism, preventing potential tissue damage caused by excessive autoimmune responses in patients with SLE.