One of the explanations is that the pathophysiology of HCV-associated type 2 diabetes mellitus consists of a defect in insulin secretion, increased hepatic tumor necrosis factor alpha, excessive hepatic glucose production, and insulin resistance, because the core-encoding region of HCV is sufficient to induce insulin resistance by the previously defined mechanism via either direct or indirect way [22]. This evidence concerns the gene TNF and type 2 diabetes mellitus.