Similar to these reports, we detected that CDK4 expression was elevated in NSCLC tissues and cells, and rescue experiments in this study showed that CDK4 knockdown abolished the promoting effects of miR-520a-5p inhibition on NSCLC cell proliferation, cell cycle progression, migration and invasion, indicating that miR-520a-5p suppressed NSCLC development by targeting CDK4. This evidence concerns the gene CDK4 and non-small cell lung carcinoma.