ERBB2 and ductal breast carcinoma in situ: Although the CNV profiles showed that 1q gain, 8p loss, and 8q gain are also common for breast invasive cancer as a whole (HER2-positive and HER2-negative) (Supplementary Figure 14), our findings are unique in that we observed that 1q gain and 8p loss can occur in DCIS even before HER2 amplification has taken place in HER2-positive breast cancer.