Fig 1: Expression of IL-21 in involved tissues of patients with IgG4-RD. (A) Representative micrographs stained for IL-21 of pancreas (left), orbital soft tissue (middle), and lymph node (right) with IgG4-RD (scale bar, 100 µm; magnification, ×100). (B) Representative micrographs were from the orbital soft tissue in IgG4-ROD patients. Immunofluorescent double staining of IL-21-positive cells (red) and CXCR5+ cells (green), cells in yellow indicate the coexpression of IL-21 and CXCR5 (scale bars, 50 µm; magnification, ×200). (C) Total IHC scores for IL-21 for patients with IgG4-RD. *P<0.05. (D) Correlation between IgG4 production and IL-21 IHC scores in orbital specimens from IgG4-ROD as determined by Spearman's rank test. IgG4-RD, immunoglobulin G4-related disease; IgG4-ROD, immunoglobulin G4-related ophthalmic disease; type 1 AIP, type 1 autoimmune pancreatitis; IgG4-RL, immunoglobulin G4-related lymphadenopathy; CXCR5, C-X-C chemokine receptor type 5; IL-21, interleukin 2; IHC, immunohistochemistry.