Additionally, both SLUG and TWIST1 were up‐regulated in CCLs, and SLUG levels were significantly higher in low‐grade (grade 1) DCIS relative to both grade 1 + 2 (mixed) and grade 2 DCIS (Figure 4H), exhibiting staining patterns similar to TBX3. This evidence concerns the gene TWIST1 and ductal breast carcinoma in situ.