ESR1 and breast carcinoma: Using Western blot, we also confirmed that MCF-7 has higher levels of DLC1 compared to T-47D and ZR75.1 cells (Fig 3B) To understand the functional relevance of DLC1 in ER+ breast cancer, we established stable DLC1 overexpression in T-47D (no endogenous expression of DLC1) cells using GenScript's GenEZ ORF cloning technology.