As shown in Figure 3(a), the number of invading breast cancer cells at different ERα+/ERα− ratios (100%, 70%, 40%, 20%, and 0%) was 249 ± 6, 404 ± 28, 430 ± 25, 401 ± 25, and 361 ± 20 cells, respectively. This evidence concerns the gene ESR1 and breast cancer.