With regard to the intrinsic molecular subtypes of BC, the Luminal A type, which is the most estrogen-responsive one, was reported to exhibit higher levels of the exomiRs miR-142-5p and miR-320a, which might be interpreted as a compensatory mechanism to impair the estrogen response since these miRNAs are known to target ESR1 and ESRRG [175] (Table 1). This evidence concerns the gene ESR1 and breast cancer.