21.   Once in place, the capsules deliver a sustained dose of radiation to the prostate, killing fast-dividing cancer cells, but leaving normal tissue largely unaffected.

22.   The chemotherapy drug cyclophosphamide kills rapidly dividing cells, which include cancer cells and some other cells in normal tissues.

23.   The protein is not expressed in normal tissue.

24.   The virus destroys normal prostate tissue as well as cancerous cells.

25.   They could also provide drug companies with normal human tissue to use in drug testing.

26.   They also kill fast-dividing normal tissues such as stomach or skin cells.

27.   When they are removed surgically, scar tissue can form that is not elastic and pliable like normal tissue.

28.   Yet potent beams of X-rays focused correctly can destroy cancers while leaving normal tissue unscathed.

29.   Cancer cells grow faster than normal tissue.

30.   It is thought to be an autoimmune disorder, meaning the disease-fighting immune system mistakes normal tissue as foreign.