Furthermore, treatment of AF cells with either RAD control peptides or function blocking RGD peptides had no effect on the baseline gene expression levels of ADAMTS -4 or type I collagen in AF cells derived from non-degenerate and degenerate IVDs respectively, suggesting that basal gene expression for these two genes occurs independently of RGD – recognising integrins. The gene discussed is ADAMTS4; the disease is atrial fibrillation.