Editing Stem cell (section)

===Disadvantages===
Stem cell treatments may require [[immunosuppression]] because of a requirement for radiation before the transplant to remove the person's previous cells, or because the patient's immune system may target the stem cells. One approach to avoid the second possibility is to use stem cells from the same patient who is being treated.

Pluripotency in certain stem cells could also make it difficult to obtain a specific cell type. It is also difficult to obtain the exact cell type needed, because not all cells in a population differentiate uniformly. Undifferentiated cells can create tissues other than desired types.<ref>{{Cite journal |date=2000-03-04 |title=Before We Are Born: Essentials of Embryology and Birth Defects, 5th edition |url=https://doi.org/10.1016/s1526-9523(99)00026-4 |journal=Journal of Midwifery &amp; Women's Health |volume=45 |issue=2 |pages=192–192 |doi=10.1016/s1526-9523(99)00026-4 |issn=1526-9523| vauthors = Moore KL, Persaud TV, Torchia MG | location = Philadelphia, PA | publisher = Saunders, Elsevier}}</ref>

Some stem cells form tumors after transplantation;<ref name = "usn2009">{{cite news|first=Bernadine |last=Healy |url=http://health.usnews.com/health-news/blogs/heart-to-heart/2009/03/04/why-embryonic-stem-cells-are-obsolete |title=Why Embryonic Stem Cells are obsolete|publisher=US News and world report |access-date=Aug 17, 2015}}</ref> pluripotency is linked to tumor formation especially in embryonic stem cells, fetal proper stem cells, induced pluripotent stem cells. Fetal proper stem cells form tumors despite multipotency.<ref>{{Cite web|url=https://www.scientificamerican.com/blog/news-blog/embryonic-stem-cells-cause-cancer-i-2009-02-19/|title=Fetal stem cells cause tumor in a teenage boy|first=Coco|last=Ballantyne|website=Scientific American}}</ref>

Ethical concerns are also raised about the practice of using or researching embryonic stem cells. Harvesting cells from the blastocyst results in the death of the blastocyst. The concern is whether or not the blastocyst should be considered as a human life.<ref>{{cite journal |title=Ethical Issues in Stem Cell Research |last1=Lo |first1=Bernard |last2=Parham |first2=Lindsay |journal=Endocrine Reviews |publisher=NIH |date=May 2009 |volume=30 |issue=3 |pages=204–213 |doi=10.1210/er.2008-0031 |pmid=19366754 |pmc=2726839 }}</ref> The debate on this issue is mainly a philosophical one, not a scientific one.