Accumulating evidence has suggested that systemic inflammation related to cancer is a pivotal mediator for the progression of cancer cachexia, and several pro-inflammatory cytokines released by both tumours and the host’s immune system, including interleukins (IL) 1, 2 and 6, interferon γ and TNF-α, have been implicated in the pathogenesis of cachexia in GI cancer. This evidence concerns the gene TNF and cancer.