The Annexin family of calcium binding proteins is composed of at least ten mammalian genes. It is characterised by a conserved core domain which binds to phospholipids in a Ca2+ dependent manner and a unique amino terminal region which may confer binding specificity. The Annexin family has been implicated as regulators of such diverse processes as ion flux, endocytosis and exocytosis, and cellular adhesion. When overexpressed in A431 cells, Annexin VI causes a partial reversal of the transformed phenotype.