To identify which miRNA-target pairs are more likely to display regulation, we used AGO2-PAR-CLIP [17] to capture biochemical miRNA targets and define their specific location within 3′ UTRs and CDSs, in the MCF7 luminal subtype and ER-positive/HER2-negative breast cancer ductal cell line [27]. This evidence concerns the gene ESR1 and breast carcinoma.