Therefore, we selectively analyzed all HER2+ patients and found that compared with HER2+ DCIS patients, HER2+ DCIS-Mi patients had larger tumors (P < 0.001), HR negative (P = 0.015), and higher Ki-67 expression (P = 0.003) and high TILs (P = 0.002). This evidence concerns the gene ERBB2 and ductal breast carcinoma in situ.