TB-500 and thymosin β4: separating the fragment from the full protein

A lot of discussion treats TB-500 and thymosin β4 as the same thing. They aren't. Thymosin β4 is a 43-amino-acid actin-binding protein. TB-500 is a short synthetic fragment based on its actin-binding region, and most of the published biology was done on the full protein. Key papers on the parent protein: 1. Goldstein et al. (Expert Opin Biol Ther, 2012), a review of thymosin β4 in wound, heart and eye repair models. https://doi.org/10.1517/14712598.2012.634793 2. Mannherz & Hannappel (Cell Motil Cytoskeleton, 2009), on how the β-thymosin family binds actin and controls cell movement. https://doi.org/10.1002/cm.20371 3. Smart et al. (Ann N Y Acad Sci, 2010), on thymosin β4 and new blood-vessel growth in the heart's outer layer. https://doi.org/10.1111/j.1749-6632.2010.05478.x For discussion: how much of the full-protein work can reasonably be read across to the fragment? Has anyone found studies that test the fragment directly? The full write-up is in Guides: TB-500 Research.