TGFB1 and atrial fibrillation: Circulating biomarkers of C-reactive protein (CRP), transforming growth factor beta-1 (TGF-β1), collagen III N-terminal propeptide (PIIINP) and suppression of tumorigenicity 2 (ST2) are found to be linked with AF, and these biomarkers may reflect inflammatory or profibrotic processes or in response to pressure or volume overload [4–7].