TNFSF13B and atrial fibrillation: As for the four common genes from WGCNA modules (HCST, PSMB9, STAT2, TNFSF13B), the HCST showed significant differences between the control/AF group (Figure 4c) and the healthy/COVID-19 group (Figure 4d), while the STAT2 showed significant differences between the healthy and COVID-19 groups.