Furthermore, IF staining showed significantly higher expression levels of carboxymethyl lysine (CML) in EP and AF tissue of Vhl cKO mice compared with the levels in control mice at the age of 8 months, indicating high levels of oxidative protein damage (Fig. 6m, p, q).44 These findings show that aberrant Hif1α activation in Vhl cKO mice induced mitochondrial dysfunction during DDD progression. This evidence concerns the gene VHL and atrial fibrillation.