As a variety of endogenous factors (e.g. glucocorticosteroids, ILs, IFNγ, TNF-α) are involved in the induction of the synthesis of intracellular MT, one may suggest that this may lead to an overprotection of tumour cells against apoptosis, and, on the other hand, supporting the metastatic behaviour of the tumour (Karin et al, 1985; Karasawa et al, 1987; Nath et al, 1988; Schroeder and Cousins, 1990; Sato and Sasaki, 1992; Tsangaris and Tzortzatou-Stathopoulou, 1998; Miles et al, 2000; Nishimura et al, 2000). Here, TNF is linked to neoplasm.