Cadherins are glycoproteins involved in Ca2+-mediated cell-cell adhesion. The cadherin repeat domains occur as tandem repeats in the extracellular regions, which are thought to mediate cell-cell contact when bound to calcium. They play numerous roles in cell fate, signalling, proliferation, differentiation, and migration; members include E-, N-, P-, T-, VE-, CNR-, proto-, and FAT-family cadherin, desmocollin, and desmoglein, a large variety of domain architectures with varying repeat copy numbers. Cadherin-repeat containing proteins exist as monomers, homodimers, or heterodimers.