41.   Authorities are extremely cautious about chronic wasting, however, because scientists are not certain what causes the disease or how it is transmitted.

42.   At the time, there were no published scientific studies either way on whether implants caused disease.

43.   Barrie Carmichael, a spokeswoman for Dow Corning, said Wednesday that the settlement is by no means an admission that implants cause disease.

44.   Before genetic drugs can be developed to attack a specific disease, researchers must understand exactly how that gene causes the disease in the first place.

45.   Beryllium dust has been known for decades to cause beryllium disease, a potentially fatal lung disease -- something Rocketdyne said it was aware of and took precautions against.

46.   Both diseases are caused by parasitic protozoans.

47.   A California startup called DNA Sciences is introducing a Web site this week that will recruit people to donate their DNA to help find genes that cause disease.

48.   A protozoan parasite in the tick causes the disease by invading red blood cells.

49.   A misalignment of the vertebrae could cause disease or prevent general health because it could interfere with the nerves, chiropractors believed.

50.   A leading theory is that abnormal variants of a certain protein cause the diseases.