To observe the link between PAK4 expression and chemoresistance in NSCLC in detail, the mRNA and protein levels of PAK4 were assessed in cisplatin-sensitive NSCLC cells (A549 and NCI-H520 cells) and cisplatin-resistant NSCLC cells (A549-res and NCI-H520-res cells) using qPCR and western blotting. This evidence concerns the gene PAK4 and non-small cell lung carcinoma.