Gastrins, iron homeostasis and colorectal cancer

► Gastrins bind two ferric ions with micromolar affinity. ► Binding of iron to non-amidated gastrins is essential for biological activity. ► Gastrin interacts with, and may catalyse the loading of, transferrin with iron. ► Concentrations of circulating gastrins are increased in hemochromatosis. ► Transferrin saturation positively correlates with circulating gastrins.