A Shift in Scientific Understanding

The term “stem cell therapy” understandably suggests that we inject a cell that directly becomes new tissue. However, decades of research have shown that this is not how these cells function in clinical use today.

In 1991, Arnold Caplan, PhD (Case Western Reserve University) first described the mesenchymal stem cell (MSC) — a cell capable of regenerating tissue.
By 2017, after extensive research, he published “Time to Change the Name,” demonstrating that these cells do not become new tissue directly.
Instead, they act as Medicinal Signaling Cells — abbreviated MSC — because they secrete growth-factor-rich extracellular vesicles (exosomes) that activate the patient’s own local tissue-specific progenitor cells to repair injury.