 Since then, Kirschner's lab has attracted many students and post-docs from theoretical backgrounds who wish to make the transition into biology.His lab is now a leader in using mathematical tools to analyze signaling pathways, cell size control, and the selectivity of drugs.In two books co-authored with John Gerhart, Kirschner has described the cellular and developmental underpinnings of the evolution of organisms, and the concept of "evolvability".