As for the tenogenic and chondrogenic genes (Scleraxis, Tenascin, Tenomodulin, Mohawk, and SOX-9) that were shown to be expressed in the AF tissue8,37–39, the results also demonstrated that the 6% and 12% strain groups had upregulated AF-markers gene expression compared to unstrained samples. The gene discussed is SOX9; the disease is atrial fibrillation.