It is worth emphasizing that this treatment is therefore used in at least some cases of each of the classic molecular subtypes of breast cancer [2], including luminal subtypes (in the larger, high grade, node-positive or HER2 positive cases), the HER2-enriched subtype (in combination with HER2-targetting therapies), and the triple negatives (for which there are currently no alternative systemic treatments in the primary setting). Here, ERBB2 is linked to breast cancer.