β-catenin is a multifunctional protein required in both cell-cell adherens junctions and canonical Wnt signalling. It is involved in a variety of developmental processes and is critical in heart development, one of the first functional organs to develop during vertebrate embryogenesis. In this book, the authors discuss the structure, function and clinical significance of β-catenin. Topics include the role of β-Catenin in the context of oral squamous cell carcinoma and its clinical implications; how β-Catenin/TCF4/Survivin signaling determines the properties and fate of human corneal epithelial stem cells; β-Catenin in kidney fibrosis and cardiovascular development; the role of β-Catenin in eye development, infection and inflammation; targeting the canonical Wnt/Beta-Catenin signaling pathway in hematological malignancies; and the clinical significance of Beta-Catenin in immunological disease and dysfunction.