Tissue examination of IgG4-RD lesions revealed that CD4+SLAMF7+ cytotoxic T lymphocytes (CTLs) and granzyme A–expressing CD8+ CTLs were the dominant infiltrating T cells, and circulating CD4+ CTLs decreased with improvement of symptoms (9–11). The gene discussed is CD4; the disease is immunoglobulin G4-related sclerosing disease.