The same group has further directly demonstrated that B cells obtained from IgG4-RD patients could produce many different profibrotic molecules including PDGFB for stimulating collagen production from FBs, lysyl oxidase like 2 (LOXL2) for extracellular matrix remodeling and various chemotactic factors (CCL4, CCL5, CCL11) for chemo-attraction and activation of FBs [114]. The gene discussed is LOXL2; the disease is immunoglobulin G4-related sclerosing disease.