Enteroendocrine cells in the gastrointestinal tract and several other endocrine cells, e.g. islet cells in pancreas, parathyroid and adrenal gland exhibited strong immunoreactivity. Normal tissues generally showed cytoplasmic positivity. Additionally displayed the intestine strong membranous positivity which was also observed in cytotrofoblasts of the placenta. All muscle types exhibited distinct staining.
Most tumors displayed weak to moderate cytoplasmic staining, in several tumors, e.g. colo-rectal and stomach cancers, combined with strong membranous positivity. Similar to normal endocrine cells displayed malignant carcinoids distinct immunoreactivity.
