Abstract: Isolated porcine pancreatic cells, isolated populations of such cells and methods for isolating and using the cells to treat subjects with diseases characterized by insufficient insulin activity are described. The porcine pancreatic cells are preferably non-insulin-secreting porcine pancreatic cell having the ability to differentiate into an insulin-secreting cell upon introduction into a xenogeneic subject, such as a human subject. Such cells include embryonic porcine pancreatic cells obtained from embryonic pigs between about day 31 and day 35 of gestation. The porcine pancreatic cells can be modified to be suitable for transplantation into a xenogeneic subject, for example, by altering an antigen (e.g., an MHC class I antigen) on the cell surface which is capable of stimulating an immune response against the cell in the subject (e.g., by contact with an anti-MHC class I antibody, or a fragment or derivative thereof).