CDH1 and CDH1-related diffuse gastric and lobular breast cancer syndrome: Inactivated sequence variations in the CDH1 gene have been frequently described as the cause of E-cadherin protein deregulation in invasive LBC.26,27,28,29 In this study, all sporadic LBCs had a second structural CDH1 somatic sequence variation (Table 3); intragenic LOH and methylation were detected in 42.9% and 28.6% of LBCs, respectively.