Thymosin β4 (Tβ4) was first isolated in the ‘60ies from calf thymus and was initially perceived as a thymic hormone with immunological effects on lymphocytes. It was then identified as a G-actin binding protein, featuring numerous functions in the human body including blood clothing, tissue regeneration, angiogenesis and tumor metastasis. Tβ4 is also involved in anti-inflammatory and neurodegenerative processes. The exact mechanisms of action of Tβ4 are still unknown, and the binding of the G-actin protein cannot itself explain the multi-activity of Tβ4. We hypothesize that the property of Tβ4 regulating the numerous physiological processes involving Tβ4, is its essential metal – binding ability.