A great number of researches have demonstrated the involvement of aberrant epigenetic modification in many diseases, including Alzheimer’s disease and many other age-related diseases (18), as for the epigenetic modification in the IVD, we detected a relatively high expression of the inhibitor of DNA binding 1 protein (ID1) in both NP (mostly in cluster 4) and AF cells. The gene discussed is ID1; the disease is atrial fibrillation.