CLCA2 and breast carcinoma: The results indicate that CLCA4 is also induced by stress and by conditions that promote epithelial differentiation such as growth on permeable membranes or suspension in extracellular matrix; that CLCA4 is required to maintain differentiation, as its attenuation caused EMT; and that ectopic expression of CLCA4 similarly inhibits proliferation of breast cancer cells, as transduction of either CLCA2 or CLCA4 into MCF7 resulted in microcolonies of enlarged cells.