CDK4 and non-small cell lung carcinoma: Recent studies have demonstrated that the ectopic expression of miR-34b-3p, which is downregulated in non-small cell lung cancer (NSCLC) tissues and cell lines such as A549 and H1299, inhibits cell proliferation and cell cycle progression and induces apoptosis by targeting CDK4, a key regulator of G1 phase progression [30].