TNF and cancer: Although animal studies using TNF-α in high dose can induce significant anti-cancer effects, (Locksley et al, 2001; Balkwill, 2002, 2006), lower levels of TNF-α may be involved in cancer promotion, tumour growth and metastasis, either directly or by a network of cytokines, chemokines and matrix metalloproteinases (Moore et al, 1999; Locksley et al, 2001; Balkwill, 2006).