miR-125a-5p acts as a suppressor of hepatocellular carcinoma, gastric cancer, breast cancer, lung cancer, glioma, and melanoma, with several proven target molecules, including SIRT7, PI3K, E2F3, ERBB2, TSTA3, HDAC4, HDAC5, EGFR, Gab2, and Lin28B [14–24]. The gene discussed is ERBB2; the disease is breast carcinoma.