11.   A slide that once appeared to show only a field of healthy cells suddenly reveals a string of cancer cells on the move, a metastasis.

12.   According to the theory, the virus inserts its deadly genetic material into the chromosomes of healthy prostate cells.

13.   Also, the laser can injure healthy cells.

14.   But Mack argued there is a difference between cloning people and therapeutic cloning that develops healthy cells that can replace damaged or diseased cells.

15.   But there are different proteins in different types of cells, in sick versus healthy cells, and even at different stages of life.

16.   By influencing how much water stays inside our cells, and how much stays in the bloodstream, salt is vital for controlling healthy cell size and blood pressure.

17.   Cancerous cells emit more light than healthy cells, and scientists hope that these differences could one day give doctors a new noninvasive way to detect disease.

18.   Cancer tumors seem to give off more heat than healthy cells.

19.   Compared with traditional chemo, the combinations are better able to target and kill prostate cancer cells while minimizing damage to healthy cells.

20.   Compared with traditional chemo, the combination is better able to target and kill prostate cancer cells while minimizing damage to healthy cells.