From the New York Times, an article on efforts to replicate the regenerative powers of lower animals, such as salamanders: "Stem cell therapy has long captured the limelight as a way to the goal of regenerative medicine, that of repairing the body with its own natural systems. But a few scientists, working in a relatively obscure field, believe another path to regenerative medicine may be as likely to succeed. ... it is the solution that nature itself has developed for repairing damaged limbs or organs in a wide variety of animals. ... The salamander can regenerate its limbs, its tail, its upper and lower jaws, the lens and the retina of its eye, and its intestine. The zebra fish will regrow fins, scales, spinal cord and part of its heart. Mammals, too, can renew damaged parts of their body. All can regenerate the liver. Deer regrow their antlers ... the machinery for regeneration must be a basic part of animal genetic equipment, but the genes have for some reason fallen into disuse in many species."