*4.5. Statistical Analysis*

For microRNA, we used the Shapiro–Wilk test as a normality test. Analysis of statistical signification between Th17 cells and Treg cells was conducted with the Wilcoxon test. Statistical significance between two independent groups was determined by the nonparametric Mann–Whitney U test. As for the comparison between RA, OA, and HCs, we used independent tests—the Kruskal–Wallis test with Dunn's post hoc. Correlation analysis of the mRNA with microRNA in Th17 and Treg cells was conducted by the Spearman test. Data were analyzed using GraphPad Prism software version 8.2.1. and was presented as figures. In all tested values, p < 0.05 was considered significant. The receiver operating characteristic (ROC) curves analysis, an area under curves (AUC) likelihood ratio of chi-square, and p-value were obtained by multivariable logistic regression analysis and were calculated by the R program (R Development Core Team (2008) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria ISBN 3-900051-07-0, URL http://www.R-project.org.) with R:ggplot [31] and pROC [32] packages.
