KRT7 and breast cancer: Pathological similarities (morphology, nuclear-to-cytoplasmic ratio dysregulation, atypia) between BCDOs and their parental tumors, and the molecular characteristics of BC cells observed in BCDOs through immunohistochemical staining for BC-associated biomarkers (GATA-3, P63, KI67, and CK7) 31 were shown in Figure 1d.