chimera). Since a fertilized egg has the potential to be two individuals or half of one, some believe it can only be considered a 'potential' person, not an actual one. Those who subscribe to this belief then hold that destroying a blastocyst for embryonic stem cells is ethical. Viability Viability is another standard under which embryos and fetuses have been regarded as human lives. In the United States, the 1973 Supreme Court case of Roe v. Wade concluded that viability determined the permissibility of abortions performed for reasons other than the protection of the woman's health, defining viability as the point at which a fetus is "potentially able to live outside the mother's womb, albeit with artificial aid." The point of viability was 24 to 28 weeks when the case was decided and has since moved to about 22 weeks due to advancement in medical technology. Embryos used in medical research for stem cells are well below development that would enable viability. Further Uses for Stem Cells Adult stem cells have provided many different therapies for illnesses such as Parkinson's disease, leukemia, multiple sclerosis, lupus, sickle-cell anemia, and heart damage (to date, embryonic stem cells have also been used in treatment), Moreover, there have been many advances in adult stem cell research, including a recent study where pluripotent adult stem cells were manufactured from differentiated fibroblast by the addition of specific transcription factors. Newly created stem cells were developed into an embryo and were integrated into newborn mouse tissues, analogous to the properties of embryonic stem cells. Stated views of groups Government policy stances Europe Austria, Denmark, France, Germany, Portugal and Ireland do not allow the production of embryonic stem cell lines, but the creation of embryonic stem cell lines is permitted in Finland, Greece, the Netherlands, Sweden, and the United Kingdom. United States Origins In 1973, Roe v. Wade legalized abortion in the United States. Five years later, the first successful human in vitro fertilization resulted in the birth of Louise Brown in England. These developments prompted the federal government to create regulations barring the use of federal funds for research that experimented on human embryos. In 1995, the NIH Human Embryo Research Panel advised the administration of President Bill Clinton to permit federal funding for research on embryos left over from in vitro fertility treatments and also recommended federal funding of research on embryos specifically created for experimentation.