Dr. Halberg’s research uses new animal models and a unique set of colorectal polyps from humans to understand how potentially cancerous tumors are initiated and established. Contrary to a longstanding paradigm in the field of cancer biology, his lab has found that tumors are often derived from multiple rogue cells—and that some tumors carry mutations in genes that drive progression and express a transcriptional program that foretells a pathologic fate. His team aims to fully understand the recruitment process in which one rogue cell transforms neighboring cells, and the consequences of early intratumoral heterogeneity on tumor biology. Their work, which is supported by grants from the National Institutes of Health, has implications for the development of personalized screening guidelines and personalized treatment strategies.