In the research by Parthenakis et al. [20], the occurrence of AF in patients with DCM was related to higher concentration of IL-6 (p = 0.001), TNF-α (p = 0.002), soluble tumor necrosis factor receptor inhibitor (sTNFRI) (p = 0.023), N-terminal atrial natriuretic factor (NT-ANP) (p < 0.001), NT-proBNP (p = 0.003), decreased exercise tolerance and lower maximum oxygen consumption at exercise peak compared to patients in sinus rhythm. The gene discussed is TNF; the disease is atrial fibrillation.