TNFRSF13C and immunoglobulin G4-related sclerosing disease: The percentages of BAFF-R + Breg cells were significantly lower in IgG4-RD patients compared with HC (69.47 ± 35.31%, 94.66 ± 11.23%, respectively; P = 0.01), while there was no significant difference compared with pSS patients (93.58 ± 10.69%; P = 0.15; Figure 2C).