[43] performed a microarray analysis of beagle lumbar IVDs to compare the gene expression differences among AF cells, NP cells and ACs; their findings showed that mRNA levels of alpha‐2‐macroglobulin, keratin (KRT) 18 and neural cell adhesion molecule (CD56) were expressed more in NP than in both AF and ACs. The gene discussed is CHL1; the disease is atrial fibrillation.