11.   But the same techniques that could be used to create cloned children can also be used to create cloned human embryos for medical research.

12.   Companies such as Advanced Cell Technology hope to obtain embryonic stem cells from cloned embryos but have had only limited success.

13.   For all anyone knows, a woman somewhere on this globe might be pregnant with a cloned embryo or already the mother of a cloned baby.

14.   For many cloning applications, it is desirable to alter the genes of the cloned embryo before growing it to term.

15.   Geron, he said, wants to create human cloned embryos to learn about how adult cells revert to primordial status.

16.   He said he hoped that within a few months the company would be able to harvest stem cells from its cloned embryos.

17.   His own group, he said, expects to impregnate a woman overseas with a cloned embryo this year, with a birth to follow next year.

18.   If the cloned embryos survive, First will implant them in a week into the uteri of cows.

19.   Last Thanksgiving, Worcester-based Advanced Cell Technology Inc., after months of attempts, successfully produced the first cloned human embryos.

20.   Like Jaenisch, most cloning researchers work on therapeutic cloning, aiming to extract stem cells from days-old cloned embryos.