Several mechanisms have been proposed for the inactivation of the cadherin/catenin complex in tumour cells, such as mutations in the genes for E-cadherin, α-catenin, and β-catenin (Hirano et al, 1992; Oda et al, 1994; Oyama et al, 1994; Machado et al, 1999), hypermethylation around the promoter region of the E-cadherin gene (Yoshiura et al, 1995), and aberrant tyrosine phosphorylation of β-catenin (Behrens et al, 1993). The gene discussed is CDH1; the disease is neoplasm.