An analysis of the NOAH study found that HER2-enriched tumours showed a higher pathological complete response rate following trastuzumab therapy compared with non-HER2-enriched clinically HER2 + tumours.33 Patients in the METABRIC cohort had not received trastuzumab, and it remains to be demonstrated if the IntClust 5 group respond better to HER2-targeted agents. Here, ERBB2 is linked to neoplasm.