Metastasis is a major cause of death in cancer patients. According to the inverse relationship between migration and E-cadherin levels in vitro, it has been proposed that invasion and metastasis of the surrounding tissues begin after the loss of the intercellular adhesion protein E-cadherin. However, this hypothesis is inconsistent with the observation that the majority of breast cancers are invasive ductal carcinomas and express E-cadherin in the primary tumor and…