The animal world is full of clever solutions to bioengineering challenges.

Can mice with humanlike tissues better model drug effects in people?

Ethical issues attend the creation of animal-human chimeras.

A study suggests that some mouse models do not accurately mimic human molecular mechanisms of inflammatory response, but other mouse strains may fare better.

A German ethics council weighs in on the discussion about the use of human-animal chimeras in research.

A UK panel puts forth guidelines for research that use experimental animals harboring human cells and tissues.