It’s late at night and you can’t seem to find the light switch, but thanks to your feline friend, Mr. Banner, you're able to make it to the bathroom without issue. This scenario, of course, is only plausible thanks to the genetic alteration that turned cats into glow-in-the-dark playthings. Inserting rhesus macaque and jellyfish genes into unfertilized cat eggs produces a fluorescent kitten resistant to feline immunodeficiency virus. More than just a convenient nightlight, the Mayo Clinic scientists responsible for this line hopes to use it to fight the human strain of AIDS. Along with cats, scientists have created glow-in-the-dark pigs, mice, dogs, and fish.