TGFB1 and metabolic syndrome: And as we present in the review article, transforming growth factor β1 (TGF-β1) is a one of the main pro-fibrotic cytokine in atrial remodeling; tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) are central pro-inflammatory mediators that are elevated in metabolic syndrome and have been linked to AF pathogenesis; galectin-3 (Gal-3) is a lectin that promotes atrial fibrosis and is predictive of AF and galectin-1 (Gal-1) similarly regulates immune responses and has emerging relevance in cardiac tissue remodeling (Table 1).