Adult stem cells, similar to embryonic stem cells, have the ability to differentiate into more than one cell type, but unlike embryonic stem cells they are often restricted to certain lineages. The ability of a stem cell of one lineage to become another lineage is called transdifferentiation. Another claim of proponents about the importance of embryonic stem cell research is the application of such cells to treat ailments like cardiovascular diseases, spinal cord injury, Alzheimer’s and Parkinson’s as well vision impairment and diabetes. The stem cell controversy is the consideration of the ethics of research involving the development, use, and destruction of human embryos. Most commonly, this controversy focuses on embryonic stem xtrmtracker.com all stem cell research involves the human embryos. For example, adult stem cells, amniotic stem cells, and induced pluripotent stem cells .