IL6 and cancer: In particular, the pro-inflammatory cytokine interleukin-6 is likely to be important in this catabolic process since it is known to act on the central nervous system to reduce appetite (Havel, 2002), results in increased substrate oxidation when infused (Stouthard et al, 1995) and is recognised to be associated with weight loss in cancer patients (Fearon et al, 1991; Scott et al, 1996).