MMP13 and atrial fibrillation: The results of MMP‐13 and ADAMTS‐4 in the AF showed that compared with the Ctrl group mice (Fig. 6G, MMP‐13: 27.97% ± 4.38%; Fig. 6H, ADAMTS‐4: 20.50% ± 7.41%), the positive cell ratios in the Saline group mice were significantly increased (MMP‐13: 42.80% ± 2.57%, P<0.001; ADAMTS‐4: 68.00% ± 6.83%, P<0.001), and the injection of ANG‐2 NAb significantly reduced the positive cell ratio of these biomarkers of IVDD (MMP‐13: 35.38% ± 8.59%, P = 0.001; ADAMTS‐4: 51.25% ± 5.97%, P = 0.004).