CCL18 was identified previously as a chemokine with fibrotic activity and selective chemotactic activity on peripheral blood T lymphocytes, especially Th2 cells.27 We have already reported that CCL18 was associated with the development of severe fibrosis in IgG4-RD.8 In addition, previous data, indicating that tissue-infiltrating and circulating IgG4-positive cells in IgG4-RD are polyclonal,28 suggest that there are many antigen responses in local lesions. This evidence concerns the gene CCL18 and immunoglobulin G4-related sclerosing disease.