""" In 1952, a scientist named Charles Breedis injected coal tar and other known carcinogens into the arms of more than 500 newts — amphibians related to salamanders that can also regenerate. Only two animals grew tumors. Much more often, the newts responded by sprouting an extra arm. If scientists can crack how a carcinogen triggers that kind of regenerative growth, it would be “some kind of holy grail” for this area of research, Whited said. """

the article has an editorial tone around the distinction of lab vs. natural populations. it starts with an acknowledgement of the consequences of the lab on the animals (losing limbs).

hard to argue with the holy grail, tho.