Immunohistochemical analysis showed that the expression levels of α‐SMA and collagen III were obviously higher in the atrial tissues of the AF‐control and AF‐AdNull groups than in the Sham group, and this increase was strongly attenuated in the atrial tissues of the AF‐Adc‐Ski group (Figure 3B‐D). Here, ACTA1 is linked to atrial fibrillation.