Reasons: They’re small and easily bred, and 99 percent of mouse genes (and likely rat genes too) correspond to human ones. Here, recent rodent-based research.

†Fighting AIDS and breast cancerInvestigators at UCSF made a mouse version of HIV, and a U. Wisconsin team created the first “knockout” rat; it was stripped of a gene that curbs human breast cancer.
†Extending the human life spanThe Methuselah Mouse Prize promises $10 million for rejuvenating an old mouse so that it lives five years instead of three.

No creatures make more sacrifices for science -- albeit involuntarily -- than the mice and rats of lab research. Some 30 million are used each year in the U.S. alone. Reasons: They're small and easily bred, and 99 percent of mouse genes (and likely rat genes too) correspond to human ones. Here, recent rodent-based research.



Fighting AIDS and breast cancer
Investigators at UCSF made a mouse version of HIV, and a U. Wisconsin team created the
first "knockout" rat; it was stripped of a gene that curbs human breast cancer.



Extending the human life span