CDH1 and breast cancer: Indeed, one of the first studies addressing the contribution of CDH1 mutations to the absence of E‐cad expression found that 55% (21 of 38 cases) of breast cancers from the lobular subtype harboured CDH1 genetic alterations.15 In a subsequent study, Berx and colleagues13 found somatic mutations of the E‐cad gene at a comparable frequency: 56% (23 of 41) of lobular carcinoma cases analysed showed E‐cad mutations.