To further determine the relationship between NF-κB activity and NSCLC cell growth inhibitory effect of PL, A549 and NCI-H460 cells were transfected with p50 siRNA using a transfection agent for 24 h, and then treated with PL (10 μM) for 24 h. This evidence concerns the gene NFKB1 and non-small cell lung carcinoma.