ERBB2 and breast lobular carcinoma: Although luminal‐type lobular carcinomas have potentially favorable features such as an ER/PR positive, HER2‐negative phenotype with low proliferative activity, there is still a controversy whether luminal‐type ILBCs do differ in outcome from stage‐matched invasive ductal carcinomas of no special type (NST) [1, 2, 3].