Pancreatic beta cells: responding to the matrix.

In a recent issue of Developmental Cell, Nikolova et al. (2006) make the unusual discovery that, unlike most epithelial cells, pancreatic beta cells do not produce a basement membrane of extracellular matrix. Rather, the matrix is provided to a subset of beta cells by local capillary endothelial cells, explaining in part how the endothelium helps promote optimal levels of insulin production.