It is, however, also emphasized that overexpression of MT-I/II might have both anti-oncogenic and oncogenic potential, since, in initial stages of tumour development, they may suppress mutation, while in tumour cells, they may promote accelerated growth and survival of neoplastic cells preventing the binding of tumour suppressor gene p53 to DNA or inducing a reversible conformation of wild-type p53 to the mutant form by binding zinc ions to cysteinyl residues [16, 18, 31, 32]. The gene discussed is TP53; the disease is neoplasm.