Abstract

The natural source for new pancreatic beta cells is an important issue both for understanding the pathogenesis of diabetes, and for possibly curing diabetes by increasing the number of beta cells. Dor et al.1 investigated beta‐cell renewal and regeneration by genetic lineage analysis in mice during physiological growth and after partial pancreatectomy. The data conclusively showed that beta‐cell replication was the only source for new beta cells without contributions from stem cells or other non‐beta cells. This underlines the capacity for beta‐cell self‐renewal and casts doubt that other cell types are able to generate new beta cells in the intact pancreas. BioEssays 26:1156–1159, 2004. © 2004 Wiley Periodicals, Inc.