Lead researcher Thomas Skutella and his team succeeded in harvesting stable stem cells from sperm producing (spermatogonial) cells taken from routine tissue biopsies of the testes of 22 adult male humans. They showed that the cells could be coaxed into regressing to become cells from all three germ layers that form the very early stages of a human embryo.
The researchers made the conclusion that, "The generation of human adult germline stem cells from testicular biopsies may provide simple and non-controversial access to individual cell-based therapy without the ethical and immunological problems associated with human embryonic stem cells."
Stem cells are the new hope for treatments that require a person's own cells to repair and replace damaged tissue, such as in Parkinson's, Alzheimer's, and cancers. This allows the treatment to bypass the big problem of immune system rejection, since the implants share the same DNA as the host. In this case, using stem cells from male testes, the treatment would only work on men.