Researchers have now shown that they can efficiently and quickly produce human iPS cells (induced pluripotent stem cells), increasing the efficiency 100-fold. Moreover, they have done it using cells from a single human hair. The iPS cell type is equivalent to embryonic stem cells, but is produced without using embryos, eggs, or cloning. The results with iPS cells continue to mount up rapidly, making it more and more difficult to justify use of embryos, eggs, or cloning to produce human embryonic stem cells.

The results were published online in Nature Biotechnology on 17 October 2008.