Collectively, our findings indicate that metformin exerts its effect on FOXO3a through the activation of AMPK and the inhibition of protein kinase B (Akt) and MAPK/extracellular signal-regulated kinase (MEK), culminating in the suppression of stemness in paclitaxel-resistant NSCLC cells. Here, FOXO3 is linked to non-small cell lung carcinoma.