CD4 and peeling skin syndrome: In both patients and C57BL/6.NOD-Aec1Aec2 mice, activated CD4+ T lymphocytes including Th1 and Th17 cells infiltrate the salivary and lachrymal glands, and produce a variety of proinflammatory cytokines, such as IFN-γ and IL-17, which may trigger gland damage and represent a crucial element in the pathogenesis of pSS [2,34].