Yes. There are examples of drugs that target stem cells or progenitor cells. For example, erythropoietin, EPO, is a drug that expands the progenitors in the blood system to make more red blood cells. It's a widely used drug. There are other examples of drugs like that in the clinic as well. Various cytokines are used for specific applications, mostly in the blood system.
As an example of drugs that target stem cells, I think they illustrate how this will become more widespread as findings around mechanisms of stem cell functions are exploited to develop new drugs in the clinic. Therapies can involve cells, but they can also involve drugs. That's very important to remember.