In this regard, HDAC chemical inhibition is also suggested to induce the overexpression of miRNA-449a, miRNA-449b-5p, and miRNA-449c-5p in hepatocellular carcinoma [28, 45], as well as the overexpression of miRNA-449a in BC and skeletal muscle cells [22, 45, 46]. The gene discussed is HDAC9; the disease is hepatocellular carcinoma.