31.   Each time a normal cell makes a copy of itself, the telomeres get a little shorter.

32.   Early cases are often treated with lasers, which have the unfortunate side effect of destroying normal retinal cells as well as the damaged areas beneath them.

33.   For a normal cell to become a cancer cell, it must defeat the various safety circuits that protect against runaway growth.

34.   Gleevec selectively targets cancer cells without harming normal cells.

35.   Glivec blocks BRC-ABL without harming normal cells.

36.   He also used the enzymes to break up the DNA found in cancer cells in an effort to learn what made them different from normal cells.

37.   He is using a powerful computer to analyze the DNA in those tissues to see which genes are active in cancer cells but not in normal cells.

38.   He said he worried about long-term effects, noting that normal cells become cancerous in a manner similar to the way these cells were grown in the laboratory.

39.   Herceptin is the first of an expected flood of drugs designed to attack specific molecules on cancer cells while sparing normal cells from damage.

40.   In addition, the inhibitors seem to lack the toxic side effects of current chemotherapies that unavoidably kill normal cells, too.