Interestingly, retrospective HER2 IHC within the patient cohort of the UK/ANZ DCIS randomized trial demonstrated that HER2-positive DCIS were more frequently associated with ipsilateral recurrence than HER2-negative DCIS (30.2% versus 15.2%, respectively), but these recurrences were less often IBC (28.4% versus 46.5%, respectively) [12]. The gene discussed is ERBB2; the disease is ductal breast carcinoma in situ.