We found that mesenchymal markers such as Twist and vimentin were overexpressed in both primary tumors and lung metastatic sections as compared to epithelial markers (i.e., cytokeratin 19 and β-catenin), which were undetected or minimally detected in the DCIS-like structure, primary tumors, and metastatic samples (Fig 8). Here, KRT19 is linked to ductal breast carcinoma in situ.