11.   But even companies working on adult stem cells say a ban on federal funding of embryonic cell research could hurt them.

12.   But ethicists say great care must be taken in work involving human embryonic cells.

13.   But if grown in a laboratory dish, the germ cells display the ability of the embryonic cells to generate all the tissues of the body.

14.   But the Science article seems to be one of the first to report that embryonic cells were taken directly down a desired lineage by manipulation with growth factors.

15.   Chimeras are animals made from the cells of two different individuals by injecting the embryonic cells of one into the embryo of another.

16.   Dr. Lorenz Studer at Sloan-Kettering converted the embryonic cells into brain cells.

17.   During fetal development, a batch of embryonic cells known as the germline cells is sequestered as a future source of sperm or eggs.

18.   Embryonic cells may provide the ideal vehicle for gene therapy, the idea of introducing genes to correct harmful genetic defects.

19.   Embryonic cells have the power to override the division-counting system and will grow and divide indefinitely.

20.   Embryonic cells are a sort of magic clay that can be shaped into organs and tissues.