CDH1 and CDH1-related diffuse gastric and lobular breast cancer syndrome: By carrying out RNAi and known drug screens on isogenic breast and gastric cell lines with and without E-cadherin, we have identified multiple druggable vulnerabilities in E-cadherin-deficient cells which may be exploited for both the chemoprevention of HDGC and the treatment of sporadic DGC, LCIS, and LBC [8,9].