In the salivary glands of pSS patients, CXCR5, CXCR5-expressing CD4 T cells and the chemokine specifically mediating migration of CXCR5-expressing cells to the glands, CXCL13, are overexpressed [7,20,21,22,23,24,25,26,27]. This evidence concerns the gene CD4 and peeling skin syndrome.