Analysis of the IVD-specific marker genes (TNMD, BASP1, TNFAIP6, FOXF1 and FOXF2; Figure 3b) confirmed the microarray results, with expression being significantly higher in both NP and AF cells than AC cells (all genes P < 0.0001). The gene discussed is TNFAIP6; the disease is atrial fibrillation.