Inflammatory cytokines play a pivotal role in the pathogenesis of cardiac arrhythmias, with substantial evidence linking elevated levels of pro-inflammatory cytokines – such as TNF-α, IL-6, and IL-1β – to the initiation and progression of arrhythmic events in patients with heart failure, atrial fibrillation (AF), and myocardial infarction. The gene discussed is TNF; the disease is heart failure.