Moreover, elevated LPS plasma levels increase the risk of progression to chronic liver disease in hepatitis C-infected patients, as LPS binds to Kupfer cells, up-regulating the expression of proinflammatory and profibrogenic cytokines such as tumor necrosis factor alpha (TNFα), interleukin 1(IL-1), IL-6 and IL-12 [23]. This evidence concerns the gene TNF and hepatitis C virus infection.