Although CCL2 has been implicated in EGFR-TKI resistance via AKT activation, the precise downstream mechanisms are not fully understood.<h4>Methods</h4>We analyzed malignant pleural effusion samples from patients with resistant NSCLC and conducted functional assays in lung cancer cell lines with ectopic CCL2 expression or knockdown, combined with <i>in vivo</i> xenograft models. The gene discussed is CCL2; the disease is lung cancer.