21.   A human lab rat turns against his employers.

22.   He has undergone so much of it that he calls himself a lab rat.

23.   Lab rats have none at all, which has made testing difficult.

24.   Lab rats, relax.

25.   The clear ointment has been tested only on lab rats, but developers said its effects are dramatic.

26.   The clear gel has been tested only on lab rats, but developers said its effects are dramatic.

27.   The chemical has been proven to cause cancer only in lab rats, company lawyer Jere White said.

28.   The physician-astronaut has undergone so much of it that he calls himself a lab rat.

29.   They met in a hallway, Bruner said, and began talking about some promising spina bifida research on lab rats.

30.   While no one knows if this strategy will work in cancer patients, doctors have found that it appears to be highly effective when tried on lab rats.