The cadherins are a family of Ca++-dependent adhesion molecules that function to mediate cell-cell binding critical to the maintenance of tissue structure and morphogenesis. Cadherins each contain a large extracellular domain at the amino terminus, which is characterized by a series of five homologous repeats, the most distal of which is thought to be responsible for binding specificity. The relatively short carboxy terminal, intracellular domain interacts with a variety of cytoplasmic proteins, including ?-catenin, to regulate cadherin function. T-cadherin (for truncated-cadherin, also designated heartcadherin or cadherin-13) expression levels have been shown to be reduced in human breast cancers and carcinoma cells lines. Evidence suggests that