In contrast to colon carcinoma cells where extracellular Ca2+ did not induce E-cadherin or result in a shift in β-catenin from the cytoplasm to the cell membrane, Ca2+ treatment resulted in growth reduction in mock-transfected cells and in a Ca2+-responsive variant line derived from the same parental colon carcinoma cells. The gene discussed is CDH1; the disease is colon carcinoma.