Interestingly, 16 (approximately 36%) of these 45 miRNAs have previously been ascribed to “estrogen action” (that is, suppressed or stimulated under E2 or ERα ligands, regulated by ERα, regulating ERα, deregulated in breast cancer or deregulated in endocrine resistance) [16,42] (Figure 2, miRNAs with a red asterisk). Here, ESR1 is linked to breast carcinoma.