Treatment of degenerative AF cells with IL-1Ra or IL-4RAb prior to mechanical stimulation had no effect on the baseline gene expression level of aggrecan and no effect on the CTS-induced decrease in aggrecan gene expression, with aggrecan gene expression remaining significantly decreased (sixfold, P < 0.01, and fivefold, P < 0.05, for IL-1Ra-and IL-4RAb-pretreated mechanically stimulated cells, respectively) (Figure 3a). The gene discussed is ACAN; the disease is atrial fibrillation.