PDF Understanding Stem Cell Research - Knights of Columbus stem cells include stem cells taken from, among other tissues, bone marrow, fetal cord blood, fat and liver. They are able to produce many, but not all, of the two hundred or so cell types in the adult body, and are therefore called multipotent stem cells. There are scientific papers that Stem cells: What they are and what they do - Mayo Clinic Stem cells: What they are and what they do. Stem cells and derived products offer great promise for new medical treatments. Learn about stem cell types, current and possible uses, ethical issues, and the state of research and practice. Human embryonic stem cells: research, ethics and policy ...