ERBB2 and breast cancer: Of the 993 tumors analyzed, 882 had available BC subtype information: 50.8% (n = 448) were HR + /HER2-, 15% (n = 132) HR + /HER2 + , 9.8% (n = 86) HR-/HER2 + , and 24.5% (n = 216) TNBC.