The central role of B-cell hyperactivity in pSS is reflected in the American College of Rheumatology (ACR)- European League Against Rheumatism (EULAR) classification criteria, where the presence of a focal lymphocytic sialadenitis (FLS) in a labial SG biopsy (whereby a high focus score is frequently associated with large accumulation of B-cells) or positivity for circulating anti-SSA/Ro-SSB/La antibodies is mandatory in the diagnosis of pSS (36). This evidence concerns the gene SSB and peeling skin syndrome.