Hoppe et al., by means of a global miRNA screening from 1105 primary tumors of ER positive BC patients, provided data about the dysregulation of 20 miRNAs (eight downregulated and 12 overregulated); among others, miR-10a and miR-126 were predictive biomarkers of tamoxifen response in early BC disease, since they were associated with a longer relapse-free time, and the authors noticed that these miRNAs are linked with migration, invasion, and metastasis (p < 0.0001) [61]. This evidence concerns the gene ESR1 and breast cancer.