KD of HDAC1 upregulates miR-449 and downregulates c-MET expression, which inhibits tumour growth; KD of HDAC1 promotes p21 and p27 expression, inhibits cyclin D1 and CDK2 expression, and reduces cell proliferation by downregulating cyclin A expression (93–95). The gene discussed is CCNA2; the disease is neoplasm.