This week, somewhere in the neighbourhood of 7500 biologists descend upon Washington DC for the American Society for Cell Biology. I made it here today just in time to hear a lecture given by Alejandro Sanchez Alvarado, a Howard Hughes Medical Institute Investigator at University of Utah, who’s been using the planarian Schmidtea mediterranea as a model for regeneration. His website has beautiful pictures. Planarians are regenerative heroes — long know for their ability to completely redevelop from pieces as small as 1/279th of the original. And even though they’re strange – they have a mouth that doubles as an anus that Sanchez Alvarado calls a “manus” – they are actually surprisingly complex.