Although the exact causes of SS and HT have not been fully clarified, SS and autoimmune thyroid diseases represented by HT have many genetic and immunopathological similarities and have some common characteristics.[5] For example, Both SS and HT are associated with the same environmental factors including viral infections, cigarette smoking, alcohol intake, and stress.[6,7] Both labial glands and thyroid tissues under pathological conditions have lymphocyte infiltration, especially CD4+T lymphocytes.[8]. The gene discussed is CD4; the disease is synovial sarcoma.