One of our novel NP markers is DSC3. Furthermore, a higher expression in non-human NP is reported for CD24, forkhead box F1 (FOXF1), KRT8, KRT18, versican (VCAN) and SLC2A1, whereas studies on human discs already show a similar expression level of these genes in AF and NP [9,10,24,41,52,53]. This evidence concerns the gene KRT18 and atrial fibrillation.