The MDACC exceptional responders trial81 enrolled 50 patients with unifocal TNBC or HER2+ breast cancer who underwent NAC followed by imaging and percutaneous tumour bed biopsy; 31 patients had no evidence of residual disease on biopsy and had omission of breast surgery and 5-year follow-up showed no in-breast recurrences. Here, ERBB2 is linked to breast carcinoma.