CDK4 and non-small cell lung carcinoma: To confirm and extend these observations, qRT-PCR and immunoblot assays were conducted to examine ZFAS1 and ZNFX1 expression in SAEC as well as cdk-4/h-TERT immortalized HBEC, and Calu-6, H358, A549, and H841 NSCLC lines cultivated in the presence or absence of CSC for 5 days.