From Big Think: "The loss of a human limb is a tragedy. We know that once they're gone, mammalian arms and legs can't ever be restored. But if you cut off a salamander's leg - or tail - it will reappear in just a few weeks. ... Now, a new generation of longevity-seekers hopes to apply the power of amphibians like the salamander, the axlotl, and the worm to human medicine. ... In the future, if we had the ability to grow a brand new heart or parts of hearts with that person's very own adult stem cells, then when we know that they have heart disease, we could just replace the heart. All of those [costly] visits to the hospital, all of the drugs, won't be required. ... Better tools will enable us to repair people rather than just sort of patching them up for a little while until they get sicker and sicker. ... Over the past few decades, scientists have begun to understand exactly how the regeneration process works in nature. When a salamander is injured, a clump of cells called a blastomea forms at the site of the wound. Like embryonic stem cells, the blastomea are especially plastic. These cells are then triggered to de-differentiate and re-initiate growth. ... Debate remains over whether they're fully pluripotent, meaning that they have the ability to form any type of tissue, or whether the cellular dynamics merely have to be reprogrammed. ... The trick, of course, is applying this knowledge to human anatomy."