Eukaryotic cells contain various Ca²⁺-effector proteins that mediate cellular responses to changes in intracellular Ca²⁺ levels. A unique class of these proteins — annexins — can bind to certain membrane phospholipids in a Ca²⁺-dependent manner, providing a link between Ca²⁺ signalling and membrane functions. By forming networks on the membrane surface, annexins can function as organizers of membrane domains and membrane-recruitment platforms for proteins with which they interact. These and related properties enable annexins to participate in several otherwise unrelated events that range from membrane dynamics to cell differentiation and migration.