Mammals didn't lose the ability to regrow limbs, they switched it off, and two growth factors can switch it back (sciencedaily.com)
The finding: the regenerative cells are already there, you just have to make them behave. After wound healing, FGF2 redirects cells toward a blastema-like structure, then BMP2 tells them to build new tissue.
A reader with permanent retinal damage noted the same trick in retinas often triggers tumors, the recurring asterisk of the whole field.
Sign in to save