Dr. Steve Elledge discusses his pioneering research in the fields of cell cycle regulation and DNA damage response. He details experiments that led to the discovery of the cyclin-dependent kinase inhibitor p21(Cip1) as well as the CHK2/DUN1 kinase, which activates signaling pathways required for the DNA damage response. He also talks about his work in the ubiquitin proteasome system and the discovery of F-box components in E3 ubiquitin ligase complexes. Enjoy.