"In 2010 experiments in longevity and age reversal on mice at the Dana-Farber Cancer Institute led to the first reversal of aging symptoms in a mammal. The mice were engineered to have damaged intestines, small testes, shrunken brains that produced no new brain cells, and a damaged olfactory sense, giving it an estimated human equivalent age of around 80. Researchers injected the mice with a drug that switched on a gene that stimulated telomerase production and the mice went on to live a perfectly normal lifespan. How significant the cancer risk from this treatment is, and if this treatment can be performed on humans or even non-genetically engineered mice is yet to be investigated."
http://en.wikipedia.org/wiki/Biological_immortality#Mice
