Microarray analysis of hepatocellular carcinoma (HepG2) and lung cancer (A549) cell lines revealed that let-7 inhibits multiple cell-cycle- and proliferation-associated genes, including cyclin A2 (CCNA2), CDC34, Aurora A [AURKA (formerly STK6)] and B [AURKB (formerly SKT12)] kinases, E2F5, CDK8, and PLAGL2, among others 46. This evidence concerns the gene CCNA2 and lung cancer.