CXCL13 and peeling skin syndrome: Serum CXCL13 levels are significantly elevated in pSS patients, and are found to correlate with clinical parameters, including rheumatoid factor (RF), κ-to-λ free light chain ratio, β2-microglobulin, γ-globulins, anti-Ro/SSA, anti-La/SSB, and erythrocyte sedimentation rate (ESR) (89, 90).