(28) cultured naïve B cells, CD19+ B-lymphocytes, memory B cells, or plasmablasts from IgG4-RD with human fibroblasts and observed that the B cells and plasma cells from IgG4-RD patients can promote collagen synthesis in fibroblasts by secreting the pro-fibrotic molecules of platelet-derived growth factor B. They also observed those cells could induce the remodeling of the extracellular matrix (ECM) by producing ECM-crosslinking enzymes, such as lysyl oxidase-like 2, and chemotactic factors CCL-4, CCL-5, and CCL-11. Here, CD19 is linked to immunoglobulin G4-related sclerosing disease.