Logically, markers of synthesis and degradation of collagen [Type I and III collagen-related biomarkers (CITP, TIMP, matrix-metalloproteinase (MMP), type III procollagen N-terminal peptide (PIIINP), TGF-b] have been investigated in relation to AF ablation outcomes. The gene discussed is TGFB1; the disease is atrial fibrillation.