In addition, CD4+ T cells or CD8+ T in the AF group produced fewer anti-inflammatory cytokines, such as IL-10, or more proinflammatory cytokines (tumor necrosis factor-α (TNF-α), IFN-γ, IL-2, IL-21) before, during, and after antiviral therapy; furthermore, the proportion of IFN-γ to IL-10 was higher in the AF group than that in the NAF group during pregnancy or postpartum. The gene discussed is IL21; the disease is atrial fibrillation.