CTS stimulation of AF cells has been shown to increase COL2A1 and aggrecan expression and decrease MMP-3 expression in human AF cells cultured in 3D collagen gels, independently of the strain magnitude (1–8% strain, 1 Hz) (Neidlinger-Wilke et al., 2005). This evidence concerns the gene COL2A1 and atrial fibrillation.