Clustering patients using IL-17A and other cytokines. A. Unsupervised hierarchical clustering analysis of IL-17A and related cytokine levels. Cluster analysis was performed by complete linkage based on Euclidean distance. B. The patient characteristics, including daily medication step, control status, and occurrence of severe exacerbation within 12 months, were compared among the groups identified in A. Statistical significance was calculated using Fisher's exact test. C. The serum levels of cytokines among the four groups identified in A. Results are shown as individual data points with median (bar) and interquartile range (box). The groups are as follows: G1 (blue dot), G2 (green dot), G3 (orange dot), and G4 (red dot).