In FACS analysis, the proportions of circulating peripheral IL-17-producing CCR6+ Th cells and FoxP3+ Tregs were increased in patients with dcSSc.In a multiple regression model (R2 = 0.995; p = 0.015) performed in dcSSc, higher IL-17 production by CD4+CCR6+ was significantly influenced by lower chronological age (p = 0.004), shorter disease duration (p = 0.033), organ involvement (p = 0.012), and increased inflammation parameters (ESR, p = 0.021; CRP, p = 0.037).Significant relative hypermethylation was seen at the gene level for RORC1 and RORC2 in SSc. The gene discussed is IL17A; the disease is systemic sclerosis.