That's why pro-lifers are trying to maintain the ban on federally funded stem cell research . Those efforts include a formal letter of protest signed by 70 members to the U.S. Department of Health and Human Services challenging HHS's ruling that stem cell research is legal. Opponents also flooded the NIH with negative comments on its proposed guidelines. And now Congressional pro-lifers are pursuing legislation to overturn the NIH guidelines. Such critics are mistaken.
Stem cells are microscopic, undifferentiated masses consisting of a few hundred cells.
Indeed, the fact that they are undifferentiated and can be coaxed into becoming a wide variety of human tissues is what makes them so valuable for research and, eventually, medical treatments. Stem cells, like all human cells, contain the normal complement of 46 chromosomes. Opponents of embryonic stem cell research have also argued that such research is no longer necessary. They point to the recent discovery that some types of adult cells can be transformed into other types of cells and claim that researchers don't have to use stem cells from embryos. To be sure, exciting progress is being made with adult cells.