Pancreatic histology (islets). Staining of Langerhans islets using immunoperoxydase with specific antibodies against insulin and glucagon (× 400). A: WRS patient; B: Normal control. In WRS patient, the majority of the cells within the islets stain for glucagon. Numerous cells also stain positively for somatostatin (not shown), and there is a marked reduction in the number of insulin-secreting β cells, which are sparse within the islets. (histological study performed by R. Bouvier and S. Collardeau-Frachon, Lyon).