His research has notably focused on the role of B cells in tissue fibrosis in patients with IgG4-RD, and the mechanisms through which CD4 + and CD8 + cytotoxic T lymphocytes may induce mesenchymal stem cell apoptosis, thereby contributing to disease progression [17, 19, 20]. The gene discussed is CD4; the disease is immunoglobulin G4-related sclerosing disease.