A lectin, Phaseolus vulgaris agglutinin (PHA), isolated from the red kidney bean, was found to have a very high affinity with gastrin-secreting cells (G cells). The unique PHA-G cell interaction is confirmed by (1) G cell reaction only with PHA, not with other lectins, and (2) PHA reaction with G cells but not with other endocrine cells. The authors concluded that gastrin-secreting cells are composed of a large quantity of galactose-N-acetyl-glucose-manose-containing glycoconjugates. The significance of this glyco-conjugate in G cells is not ascertained. The use of a PHA histochemical technic may well be suitable to study the carbohydrate (or pathophysiological) changes in G cells.