Cardiac repair
The C-terminal region of Tβ4 activates ILK. This helps move cells toward damaged tissue, support the growth of new blood vessels, promote cell survival, and activate dormant heart repair cells after injury.
Because TB-500 lacks the C-terminal region, it may not activate ILK to the same extent.
Anti-scarring effects
A 2025 study by Maar et al. found that Tβ4 helps prevent scar tissue from forming by stopping a key process: it blocks fibroblasts (regular repair cells) from turning into myofibroblasts, the cells that actually create scar tissue. It does this by shutting down a protein called ROCK1.
Researchers have not identified which part of Tβ4 is responsible for this effect, so it is unknown whether the seven-amino-acid TB-500 fragment retains the same activity.
Cell survival
Tβ4 also influences the ILK-PINCH signaling pathway, which helps regulate genes involved in cell survival and the body’s response to injury. Whether TB-500 can influence this pathway remains unknown.
This does not mean TB-500 is inactive
Philp et al. (2003) demonstrated wound-healing activity for the seven-amino-acid fragment itself. It simply means that the full-length Tβ4 protein has a broader range of biological functions than a seven-residue fragment is unlikely to fully reproduce.
Conclusion
TB-500 may retain some wound-healing activity, but the cardiac repair, anti-scarring, and cell survival functions of full-length Tβ4 may not be fully replicated by this fragment.