1.   The binding domain on the mouse leukemia virus is relatively generic, Kim said, so that the virus can bind to the receptors on most rodent cells.

2.   They happened to carry a gene that protected them against a devastating leukemia virus that was annihilating the rest of the rodents on the farm.

3.   Hagahai were found to carry a human T-cell leukemia virus but not develop the disease.

4.   Subsequent blood tests found that many Hagahai carried a human T-cell leukemia virus, although they were not afflicted with the disease.