Stem cells are cells which haven't yet differentiated and become specialized into organs or people. Stem cell research is a complex and controversial topic, too complex to analyze effectively in a blog entry, or even a thick textbook. But given all the hysteria, hype and distortion surrounding the issue, I wanted to make a few points for the sake of clarity.

* President Obama's order this week does not change legality - it is already legal to conduct research on embryos. It is still not legal to create embryonic stem cells for the purpose of research, nor should it be. What is involved here is conducting research on embryos that have been produced privately for the purpose of in vitro fertilization, but have not ended up being used. Previously the funding was mostly private, now there will be increases in federal funding. At a time when private research money is shrinking, this may help the research to continue. * At the same time, advances in treatments have come not in embryonic stem cells, but in adult stem cells that have been manipulated genetically to regain their earlier potential before they began to differentiate. Embryonic stem cells hold promise because they haven't yet differentiated and may be manipulated to do so in therapeutic directions. But this potential hasn't been realized in part because the body tends to reject these cells as foreign. In contrast, using a body's own stem cells or umbilical cord blood circumvents the risk of rejection, since a body won't reject its own cells. * The current debate reminds me of the waste in creating excess embryos for no real medical purpose in the first place. We need stricter regulations on in vitro fertilization, not only so that no more pathetic stories like Octomom occur, but also because life is precious and should not be initiated only to be wasted in this spirit of excess. IVF for an otherwise childless couple can be a wonderful thing, but it must be well monitored and carefully regulated. * It is preferable for embryos to be used for research rather than discarded, even with limited potential to lead to cures, and only with the understanding that no embryos should be created for research purposes.

When you unwrap the real science from the politics and postering, there is less controversy, and less negative emotion.

Dr. Marc Siegel is an internist and associate professor of medicine at the NYU School of Medicine. He is a FOX News medical contributor and writes a health column for LA Times, where he examines TV and movies for medical accuracy. Dr. Siegel is the author of "False Alarm: The Truth About the Epidemic of Fear"and "Bird Flu: Everything You Need to Know About the Next Pandemic." Read more at www.doctorsiegel.com

Dr. Marc Siegel, a practicing internist, joined FOX News Channel (FNC) as a contributor in 2008..