ERBB2 and breast carcinoma: This is especially important for women with ER-positive and HER2-negative breast cancer where less than 10% overall obtained a pCR but by using multigene profiles they could be separated into two distinct subgroups; those with luminal subtypes having only a 3% chance of achieving pCR compared with a >20% probability of pCR among those with non-luminal subtypes.