C3 and peeling skin syndrome: To find out whether the mRNA levels of m6A-related genes in PBMCs from patients with pSS could be indicative of disease activity, clinical manifestations and laboratory findings such as ESR, CRP, C3, C4, IgG, IgA, IgM, rheumatoid factor, anti-SSA antibody, anti-SSB antibody, ANA, WBC, RBC, HGB, PLT, lymphocyte, lymphocyte%, monocyte, monocyte%, neutrophil, neutrophil%, disease duration, and ESSDAI score were collected.