When employed in HER2pos ductal carcinoma in situ (DCIS) and patients with stage I HER2pos IBC in phase I/II trials, autologous HER2-targeted DC1 vaccination resulted in durable anti-HER2 Th1 immunity; pCR rates approached 25 % with substantial loss of target antigen in the remainder of patients (unpublished data) [15, 19]. This evidence concerns the gene ERBB2 and ductal breast carcinoma in situ.