Scientists in Germany have shown that adult stem cells with the same flexibility as embryonic stem cells can be grown from human testes tissue. Like embryonic stem cells and iPS (induced pluripotent stem) cells, these human stem cells are pluripotent, showing the ability to grow for long periods in the lab and to form representatives of most or all tissues of the body. This is not the first report of pluripotent stem cells from testes. A different German team had previously published their results producing such flexible stem cells from mouse testes, and a U.S. group had also published their results producing these flexible stem cells from mice, while a U.S. company had claimed they were able to produce flexible stem cells from human testes. However, this German group is the first to publish evidence (online in the journal Nature) that such cells can be made from human testes tissue.

According to senior author Thomas Skutella, "The advantage these cells have in comparison to embryonic stem cells is that there is no ethical problem with these cells and that they are natural." Skutella is a professor at the Center for Regenerative Biology and Medicine in Tuebingen, Germany.