Metallothioneins (MTs) are low molecular weight
proteins, which are present in almost all types of organisms. In mammals, four main MT
isoforms designated from MT-1 to MT-4 were identified. Their
biological role, according to their characteristic structure, was shown to be mostly associated with cellular metabolism of
metal ions, especially
zinc. Moreover, the available evidence suggests broad regulatory properties of MTs in the control of cell senescence and various
pathological processes including neurodegeneration, cardiovascular pathology, metabolic disorders, and various
malignancies. This extensive review provides general in formation on the structure of MT family members and the cellular functions of MT-1, MT-2, and MT-4
isoforms as well as insights into divergent
biological roles of MT-3. Due to the involvement of MT molecules in various processes related to
carcinogenesis, an organ-specific presentation of current data concerning their potential impact on the progression of various
tumors is given. The regulatory role of MT family members in the function of the immune system is also discussed in depth.