SCX and atrial fibrillation: In addition, the gene expression levels of collagen I, SCX, and CD146, along with the novel biomarkers of AF as reported by J. Wang [39] (Bpifa2f, Fibin, and Myoc), upregulated significantly when cocultured with AF cells, while no significant changes were observed in Igfbp5, MMP3, and IL-11(Fig. 1F).