Our results showed that pre-treatment with IGF1R inhibitor picropodophyllin (PPP) or NF-κB inhibitor parthenolide (PTL) significantly increased the sensitivity of PC9GR cells to gefitinib, suggesting that IGF1R/NF-κB activation was involved in the acquisition of gefitinib resistance in EGFR-mutant NSCLC. This evidence concerns the gene EGFR and non-small cell lung carcinoma.