Any of a family of proteins that act with other cell adhesion molecules to bind cells together. Catenins anchor the actin filaments of the internal cytoskeleton to the cadherin molecules that span the space between adjacent cells at adherens junctions and (in the case of β‎-catenin) at desmosomes. Together these components maintain the three-dimensional structure and function of cell layers. They are also important in determining cell fate and organization during development. Moreover, β‎-catenin functions with WNT protein in a signal transduction pathway inside cells that regulates cell development, homeostasis, and survival. Binding of WNT to its receptor on the cell surface causes a build-up of β‎-catenin inside the cell, some of which enters the nucleus where it switches on the transcription of target genes. Mutations in β‎-catenin are implicated in certain cancers.