CDH1 and breast cancer: Potential limitations of the present study include (1) use of virtual microscopy, (2) centrally but not locally stained E‐cadherin IHC, (3) restriction of cases to HR‐positive/HER2‐negative BCs (i.e. luminal BCs), (4) omission of consensus discussions in favor of a pre‐defined reference diagnosis, (5) the increased frequency of ILCs in the study collection (34%) as compared to population‐based BC cohorts (approximately 15%), and (6) composition of slide sets A and B of BCs of NST spiked with ILCs (exclusion of BCs classified as mixed BCs as per central reference diagnosis).