A randomised phase I/II trial (NCT00555152), yet to report, is assessing the effects of neoadjuvant lapatinib (a tyrosine kinase inhibitor causing dual inhibition of HER2 and EGFR) in DCIS by measuring changes in Ki67 index at the time of surgical excision. This evidence concerns the gene ERBB2 and ductal breast carcinoma in situ.