Thymosin β-4 is an endogenous pro-angiogenic, fibroblast-activating peptide that is involved in hormone regulation. Thymosin β-4 also exhibits immunomodulatory and cardioprotective activities. Thymosin β-4 improves would healing in cardiac issue and improves cardiac function in vivo. Thymosin β-4 binds G-actin filaments, preventing actin polymerization.