CDH1 and breast ductal adenocarcinoma: In this context, several studies have demonstrated that the analysis of E-cadherin expression is a powerful tool for distinguishing lobular from ductal carcinomas, even in those infiltrating and in situ tumors with indeterminate features.40, 41 Consistent with these findings, E-cadherin gene (CDH1) has been reported to be frequently mutated in infiltrating lobular carcinoma42–44 and lobular carcinoma in situ,45 but not in ductal tumors.46