Endocrine phenotype of EpCAM-positive fetal pancreatic cells. (a) shows immunostaining of 22-week fetal human pancreas to demonstrate cells in primitive pancreatic islets with coexpression of insulin and glucagon. Negative controls, where primary antibodies were omitted, are on extreme right. (b) shows isolated freshly EpCAM-positive cells with coexpression of insulin and glucagon in some cells. (c) shows EpCAM-negative fraction showing occasional cells with glucagon. Orig. mag., a, ×200; b and c, ×400.