It is a pleasure to join the other authors in this issue to honor Dr Arnold Levine and the remarkable impact of his research. Our paths crossed with Arnie’s when our genetic analyses of colorectal cancers led us to investigate the p53 gene and identify it as a tumor suppressor gene. p53 was initially identified by Arnie and others as an oncogene and tumor antigen, nearly a decade before its role as a tumor suppressor gene was revealed. We fondly remember Arnie visiting our lab, and we visiting his, to discuss the implications of the genetic alterations our group identified in human cancers and how we could work together to investigate the voluminous new questions these mutations raised.