What I found to be worrying is that the researchers seems to be unclear about how MSC is causing the improvements. Also the improvements continues after the st

What I found to be worrying is that the researchers seems to be unclear about how MSC is causing the improvements. Also the improvements continues after the stem cells have disappeared. This seems to suggest the effect doesn't come from the MSC, but rather the chemicals the cell produces. Does that mean if we can synthesis the chemicals, we don't need the cell?