EREG and breast cancer: Our data suggests that even when young patients of different populations have a Luminal early onset breast cancer, they might have more aggressive tumors compared to older patients, as we found an overexpression of AREG, EREG, and DCX in younger patients of the white population who have Luminal or HER2+ tumors, compared to older patients of the same subtype, as the overexpression of these genes is associated with poor outcomes in breast cancer patients.