CDK6 and non-small cell lung carcinoma: To better understand the mechanisms underlying cell cycle arrest induced by e4 and e12 in NSCLC cells, we assessed the expression levels of a few genes involved in cell cycle regulation, including cyclin D1 (CCND1), cyclin A2 (CCNA2), cyclin B1 (CCNB1), cyclin-dependent kinase 2 (CDK2), and cyclin-dependent kinase 6 (CDK6) in PC-9 by qPCR.