CD4 and peeling skin syndrome: Quantitative real-time PCR (qRT-PCR) studies have demonstrated that CD4+ T lymphocytes obtained from salivary gland biopsies of pSS patients express higher amounts of IL-2, IFN-γ, and IL-10 mRNA than peripheral blood CD4+ T cells, and salivary gland epithelial cells produced more IL-1, IL-6, and TNF-α mRNA than epithelial cells in normal salivary glands16.