The first thing that occurred to me was that they're building an unkillable mouse. The next thing was that we're going to be up to our armpits in mice before long.
Obviously, we need to transfer this technology to cats ASAP!
Viking Kitties, NOW!
Seriously, that was pretty much the premise of this movie. A couple of researchers decide to test their new "regeneration" serum on a fresh corpse at the hospital. Just their bad luck it happened to be a psycho killer who had recently been shot by the police... Every time the Sheriff (played by Chuck Norris) tries to kill or incapacitate the psycho, he just regenerates the damage and keeps coming.