In advanced comedo-DCIS tumors (day 47 MCF10DCIS.com xenografts), invasive cancer cells show either strong p63 and decreased/weak Her2/neu coexpression (Fig. 3, panels k-n, arrows in panels l-n), or continued coexpression of p63 and Her2/neu (Fig. 3, panels o-r). This evidence concerns the gene ERBB2 and ductal breast carcinoma in situ.