In summary, we demonstrated that the direct association of nuclear receptor RXRα with a preferred binding sequence of AGGUCA prevents pre-miR-103a-2 nuclear-cytoplasmic exporting by XPO5, resulting in the inhibition of pre-miR-103a-2 maturation into miR-103 and miR-103-mediated downregulation of Dicer in breast cancers. This evidence concerns the gene DICER1 and breast carcinoma.