Although widely hailed as a way around the ethical problem of destroying embryos in the process of harvesting stem cells, Collins said the advance of iPS was not a replacement for embryonic stem cell research.
"But of course, we still are very early in investigating this [Yamanaka's] dramatic finding," said Collins, who added that there are still a list of very legitimate questions about whether IPS cells and embryonic stem cells are equivalent.
"We'll never know the answer to that unless we do side-by-side research," said Collins.
Researchers say the new stem cell lines not only open up opportunity, but offer better research materials to scientists.
"This is long overdue," said Robert Lanza, Chief Scientific Officer of Advanced Cell Technology, Inc. Lanza's group has just filed with the FDA to begin a clinical trial using embryonic stem cells to treat juvenile blindness.
"Restricting federal research funds to research on a few cell lines created by an arbitrary date in 2001 crippled stem cell research in this country," said Curt R. Freed, Professor and Head of Division of Clinical Pharmacology and Toxicology at University of Colorado School of Medicine.
Freed points out that embryonic cells must be grown in a certain way to be used for humans and that "none of the Bush cell lines met those standards." The new lines will fix that problem.
"What's important about this is that it allows American research to proceed on lines using the best technology and the most advanced technology," said Laurie Zoloth, director of the Center for Bioethics, Science and Society at Northwestern University in Evanston, Ill.
"We've advanced both ethically and scientifically in the last eight years," she said.