Mammals typically do not regenerate body parts, this development may one day lead to medical procedures in which amputees are able to grow back missing limbs. According to New Scientist a cocktail of proteins that stimulate regeneration has promoted lab mice to grow back a greater portion of their amputated toes than was possible in the past.
In this transformational study biologists amputated toes off of mice and then treated them with a cocktail of BMP2 and BMP9 proteins, which triggered their bodies to grow back missing bones and the cartilage necessary to support toes joints in a medical first.
It was noted that the animals did not grow back complete toes, however they did get closer to a completed digit than in past studies in which the animals only grew some of the missing bones. Even if the animals had fully regenerated there would still be a great deal research needed to move from showing proof of concept where a protein cocktail can regenerate cartilage to the point where showing which proteins could be used to grow back a human limb.
Nonetheless all clinical research has a starting point somewhere, and this may be it; if their findings and progress hold up, we may be able to someday in the future find ourselves with a new way to treat amputees.