Additionally, the A549, HCC827, H1975 cell lines represent three main lung adenocarcinoma cell types that harbor wild‐type or various epidermal growth factor receptor (EGFR) mutation genotypes that are associated with sensitivity to tyrosine kinase inhibitors (TKIS) as well as a T790M missense mutation with acquired drug‐resistance to EGFR‐TKIs to reflect the antitumor effect of metformin or be combined with chemotherapy to be used as a comprehensive treatment for lung adenocarcinoma cell lines. This evidence concerns the gene EGFR and lung adenocarcinoma.