To verify the effects of lncRNA NR2F1‐AS1 on breast cancer angiogenesis, we first established the breast cancer cell line knock‐down of lncRNA NR2F1‐AS1 (MDA‐MB‐231‐sh‐NR2F1) compared with the negative control (MDA‐MB‐231‐sh‐NC), and overexpressing lncRNA NR2F1‐AS1 (MCF‐7‐lenti‐NR2F1) compared with the control group (MCF‐7‐lenti‐Vec) through lentivirus transfection (Figure 2A). This evidence concerns the gene NR2F1 and breast cancer.