TNFRSF13C and immunoglobulin G4-related sclerosing disease: Similarly, the MFI of BAFF-R on memory B cells was not statistically different in the three groups (IgG4-RD: 280.1 ± 124.2; pSS: 286.8 ± 101.0; HC: 364.2 ± 140.7; P = 0.10).