Fig 1: Macrophages and monocytes in controls and atrial fibrillation (AF) groups, analyzed by scRNA-seq.A Uniform manifold approximation and projection (UMAP) of macrophages and monocytes in from 4 control samples obtained from 2 sites of 2 donors (openly published datasets of healthy donors) and AF groups. macs, macrophages; monos, monocytes. B Proportions of each macrophage and monocyte sub-cluster in the control (blue) and AF groups (red). Data were expressed as median with interquartile range and compared using Wilcoxon rank-sum testing. C A volcano plot of genes in IL1B+ macrophages-1 (My.1) and non-classical monocytes (My.6) exhibiting differential expression between the control and AF groups (non-parametric Wilcoxon rank sum testing). Blue: upregulated in controls; red: upregulated in AF samples. The thresholds were log(p) > 10.0 and average log2(fold change) > 0.5 (for AF samples) or log2(fold change) < −0.5 (for controls). D Feature plot of AREG expression in macrophages and monocytes. E AREG expression in each macrophage and monocyte sub-cluster (scRNA-seq data). Wilcoxon rank-sum testing. F Circulating serum AREG levels (n = 15 vs 15 vs 42). Kruskal−Wallis testing followed by Dunn’s post hoc analysis. G Proportions of AREG-positive patients (n: 15 for controls, 15 for paroxysmal AF, and 42 for persistent AF). Chi-square testing. Statistical significance was expressed as *p < 0.05, **p < 0.01, or ***p < 0.001.