Beta-catenin (or β-catenin) is a protein that in humans is encoded by the CTNNB1 gene. β-catenin is a subunit of the cadherin protein complex and also acts as an intracellular signal transducer in the Wnt signaling pathway. Deregulation of beta-catenin signaling is an important event in the genesis of a number of malignancies, such as colon cancer, melanoma, hepatocellular carcinoma, ovarian cancer, endometrial cancer, medulloblastoma pilomatricomas, and prostate cancer.