11.   In the case of Dolly the sheep, scientists at the Roslin Institute near Edinburgh, England, used an adult breast cell as a donor.

12.   It is an estrogen-like compound that acts in the breast as an antiestrogen, preventing the natural hormone from stimulating the growth of breast cancer cells.

13.   Kyniston is taking Tamoxifen, an estrogen-blocking drug that can stop breast cancer cells from dividing.

14.   Meanwhile in New York, Dr. Ramon Parsons, a pathologist and cancer geneticist, had been studying breast cancer cells.

15.   Researchers from Greece and Britain report that they have synthesised a very small protein that appears to target breast cancer cells.

16.   Scientists believe that breast cells become cancerous after several genes in those cells become damaged or malfunction.

17.   She points out that environmental factors, if they are important, probably do their mischief by damaging genes in breast cells, and that both need continuing study.

18.   Scientists have found that many breast cancer cells have elevated levels of an enzyme associated with cell growth.

19.   She handed over the slides of my breast cells to Dr. Grace Yang, cytopathologist at New York University Medical Center.

20.   Some researchers think progestin may drive the proliferation of breast cells, but this is controversial.