Integrins are proteins that help cells attach to things outside the cell. There are different types of integrins, and each one interacts with certain molecules on the surface of other cells. Integrins play important roles in many cellular processes, like growth, migration, and activation of cytokines.
Integrins help the cell to rapidly and flexibly respond to events that happen on its surface. There are many types of integrins, and each cell has multiple different types on its surface. Integrins exist in all animals, while integrin-like receptors exist in plant cells.
Integrins work together with other proteins, such as cadherins, the immunoglobulin superfamily cell adhesion molecules, selectins, and syndecans, to mediate cell-cell and cell-matrix interactions. Ligands for integrins include fibronectin and vitronectin.