GZMB and immunoglobulin G4-related sclerosing disease: Given that TFR cells have been implicated in suppressing GZMK+ cytotoxic TFH cells in ectopic lymphoid follicles of patients with IgG4-related disease (35), we assessed the ratio of GZMK+TIA-1+ or GZMB+TIA-1+ TFK cells to TFR cells.