IL6 and metabolic syndrome: In summary, the pro-inflammatory cytokines IL-6 and TNF-α, the profibrotic growth factor TGF-β1, and the lectins galectin-3 and galectin-1 contribute to the construction of a common pathophysiological axis through that of metabolic syndrome, chronic inflammation, myocardial fibrosis, and atrial arrhythmogenic substrates.