From the introduction:
Just as slight variations between different sources of stem cells are crucial to understanding the real policy debate over when life begins under the law, slight permutations in the federal regulations and guidelines for stem cell research can have serious ramifications for advancing the science of stem cell research and therapeutic applications. As human embryonic stem cell ("ESC") research has garnered widespread press coverage and generated enormous public controversy for over a decade, scientists and physicians have been finding generous amounts of less controversial, adult stem cells ("ASCs") in an increasingly wide array of human tissue. These discoveries promise new and urgently needed therapies for patients but also pose novel challenges for regulators. This is especially so here, where many ASC therapies are emerging from the offices of practicing physicians instead of the laboratories of university or commercial research scientists.
Mary Ann Chirba and Stephanie M. Garfield. "FDA Oversight of Autologous Stem Cell Therapies: Legitimate Regulation of Drugs and Devices or Groundless Interference with the Practice of Medicine?." Journal of Health & Biomedical Law, 7, (2011): 33-272.