What role will stem cells play in male infertility?

The use of stem cells to treat otherwise incurable or serious human disease remains a political "hot potato." One must remember, however, that the sources of embryonic and adult stem cells are distinctly different. The use of adult stem cells avoids all of the ethical and political criticism associated with the former's fetal etiology. While not totipotential, adult stem cells still have the advantage of prolonged proliferation, self-renewal, generation of more differentiated cells, maintenance of developmental potential, and proliferation in response to injury.