CCR8 and immunoglobulin G4-related sclerosing disease: In our previous studies, we revealed that the chemokine (C-C motif) ligand 18 (CCL18) and its receptor chemokine (C-C motif) receptor 8 (CCR8) in labial salivary glands (LSGs) of IgG4-RD patients are upregulated when compared with those of healthy controls and of Sjögren’s syndrome patients [5].