Oh, we ALLOW adult stem-cell research. We pump millions into it per year. It's the fetal stuff... which is the ONLY KIND that has shown any reasonable progress in the last few years... that we limit so thoroughly.
And I was using the letter examples thinking it was understood that your combination must spell a word in order to be a viable cell type found within the body. My fault, should have clarified. But working with stem cells is like trying to spell in a language which we don't know, using characters that we've never seen before. We don't even have the benefit of knowing what those characters are until we stumble across them.
Fetal stem cells, on the other hand, seem to program themselves. They do all the work FOR us... personally, I'm still against killing fetuses to acquire them. Even if the fetuses are going to be destroyed, anyways, because then people will use it for a "well, we're using these, why can't we go to the next step?". With some types of people, you give them an inch, and they'll take the whole damned country.
