As shown in Figure 2, both serum GITRL and sGITR levels in pSS patients with extra-glandular manifestations were significantly higher than those without extra-glandular manifestations (GITRL: 8.60 ± 8.25 ng/mL versus 3.15 ± 3.13 ng/mL; P = 0.0067. Here, TNFSF18 is linked to peeling skin syndrome.