Moreover, oxidative stress (indicated by increased ROS generation, Figure 5B), myofibril degradation (indicated by decreased myosin heavy chain (MHC) expression) and collagen I deposit (Figure 5C,D) were more severe in the atria of the AF patients with the ALDH2*2 allele than in those with the wild-type. Here, ALDH2 is linked to atrial fibrillation.