IL6 and cancer: The pro-inflammatory cytokines interleukin (IL)-1β, IL-6, tumour necrosis factor (TNF)-α and interferon (IFN)-γ (also called pro-cachectic cytokines) are thought to be responsible for the metabolic changes associated with cancer cachexia through different mechanisms (Toomey et al, 1995; Argiles et al, 2003; Van Cutsem and Arends, 2005; Morley et al, 2006).