'''Embryonic stem cell''' research is the utilization of [[stem cells|stem cells]] from [[embryo]]s which can then be grown in a laboratory culture and produce specialized cells to treat [[disease]]s or used for research purposes. The most common source of such cells is discarded embryos at [[fertility clinic]]s - the process of [[IVF]] typicially produces two or three 'leftover' embryos for each treatment, which are usually dicarded. The use of embryonic stem cells in medicine has met with some controversy, particularly from the [[pro-life]] movement that is concerned about the destruction of embryos that they believe constitute human life.<ref>http://www.washingtonpost.com/wp-dyn/content/article/2005/07/29/AR2005072900158.html</ref>
'''Adult stem cell''' research is similar except it does not use destroyed embryos, and instead is based on stem cells that can be taken from adults. These cells are less versatile than those harvested from discarded embryos, but they do not raise the associated [[ethics|ethical]] dilemas <ref>http://www.isscr.org/science/faq.htm</ref> and so far have been easier to work with in achieving results.