The lack of association between the TNF-α G-308A polymorphism and plasma TNF-α concentrations in the present study is consistent with a lack of association noted in prior studies in either IDC7 or heart failure in general.12 This finding suggests that in IDC, either the TNF-2 allele is suppressed or the effect of the TNF-2 allele is overridden by other factors associated with heart failure, such as disruption of the cytokine network.19 This evidence concerns the gene TNF and heart failure.