All human peripheral blood B cell subsets expressed similar levels of the inhibitory molecule PD-L1, and the percentages of total CD19+PD-L1+ B cells as well as CD24hiCD38−PD-L1+ and CD24hiCD38hiPD-L1+ B cell subsets were lower in untreated RA patients than in HC. Here, CD274 is linked to rheumatoid arthritis.