Second, miR-206 can directly regulate mRNA expression by targeting the 3′-UTR of MET and BCL2, and inhibit protein expression of cyclin D1 and gene expression of cyclin D1, cyclin D2 and matrix metalloproteinase 9 (MMP-9), while increased p57 gene expression in lung cancer cell (A549). The gene discussed is CCND1; the disease is lung carcinoma.