Since mir-4728 is lowly expressed in most tissues and amplification or overexpression of HER2 increase the cellular concentration above a functional threshold8, inhibition of mir-4728 and the mir-4728/PAPD5/miR-21-5p circuit could act as an anti-HER2 cancer therapy that is selectively active in HER-positive cancer cells. Here, ERBB2 is linked to cancer.