Further correlation analysis of cytokines in SLE patients with sole lupus skin disease revealed that plasma IL-22 levels correlated positively with the percentage of CCR6+ Th22 cell population (P = 0.0159, r = 0.5314; Fig. 6E), and the SI (P = 0.0107, r = 0.5570; Fig. 6F). This evidence concerns the gene CCR6 and systemic lupus erythematosus.