ERBB2 and breast cancer: Parise CA and Caggiano V reported that the ER−, PR + , HER2 + luminal B breast cancer had the worst prognosis of the following 3 categories of HER2 + luminal B breast cancer: ER + , PR + , HER2 + (triple-positive breast cancer), ER + , PR−, HER2 + breast cancer, and ER−, PR + , HER2 + breast cancer.[22] In this study, as previously known, the clinical outcomes and prognosis were significantly different according to the molecular subtypes, and luminal type breast cancer generally had a better prognosis than HER2 + breast cancer and TNBC.