The sea worm Platynereis dumerilii is only a few centimeters long but has a remarkable ability: in just a few days, it can regenerate entire parts of its body after an injury or amputation. By focusing more specifically on the mechanisms at play in the regeneration of this worm’s tail, a research team has observed that gut cells play a role in the regeneration of the intestine as well as other tissues such as muscle and epidermis.