IL6 and cancer: Cancer cachectic animals exhibit increased plasma levels of cytokines, such as interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and leukemia inhibitory factor (LIF), which are either produced by cancer cells or released by the host immune system in response to the cancer (Mori et al., 1991; Inui, 2002; Ebrahimi et al., 2004; Perboni and Inui, 2006; Tisdale, 2009).