To date, the exact relationship between E-cadherin dysfunction, premalignant ALH/LCIS, and malignant ILC is unclear: ALH and LCIS share many of the same genetic aberrations as ILC and are both considered nonobligate precursors of lobular breast cancer, but a definitive pathway to malignancy between these different lesions has yet to be established9,53. Here, CDH1 is linked to atypical lobular breast hyperplasia.