Chimpanzees are not necessary for almost all biomedical research, NIH Director Francis Collins said last week in announcing the agency's plan to retire all but 50 of the 360 animals it has available for research. Few, if any, invasive experiments will remain. Eight noninvasive behavioral and genomics studies can continue, NIH said, but only if the chimpanzees are kept in appropriate conditions, such as in groups of at least seven animals, in large outdoor spaces, and with room to climb. The decision comes after years of debate. Explaining the decision, Collins said that chimpanzees share 98% of our DNA, and "they deserve special respect." Reducing their use in research is "scientifically sound and the right thing to do."