Mechanical stimulation of AF cells derived from degenerative IVDs with 10% strain at 1.0-Hz frequency for 20 minutes resulted in a significant decrease in aggrecan and type I collagen relative gene expression 24 hours post-CTS (fivefold, P < 0.01, and sixfold, P < 0.05, respectively) (Figures 3a and 3b). The gene discussed is ACAN; the disease is atrial fibrillation.