Fetomaternal cell trafficking and the stem cell debate : Gender matters

he current ethical, political, and scientific debates on stem cells pitch the benefits and limitations of 2 cell types against each other, adult vs embryonic stem cells. Embryonic stem cells derived from human blastocysts have the key advantage of pluripotency, meaning that they form nearly all cell types but also have the disadvantage of forming tumors in vivo, which may limit clinical application to tissue engineering rather than cell transplantation. In contrast, adult stem cells are derived from mature tissue, typically from bone marrow, but increasingly from most organs. In general, adult stem cells have low plasticity, although reports of differentiation outside traditional lineage boundaries suggest that some adult stem cells may be more pluripotent rather than multipotent.1 Aside from plasticity, these differing stem cell types have very different ethical issue