On the contrary, two recent reports showed that Cx43 knockdown could sensitize glioblastoma cells to temozolomide.16, 31 Especially for Cx26, its upregulation improved gemcitabine anticancer efficacy in pancreatic cancer cells.21 However, in this study, we demonstrate that Cx26 is the predominant Cx isoform expressed in NSCLC cells, and Cx26 upregulation contributes to gefitinib resistance via induction of cell EMT. This evidence concerns the gene GJA1 and non-small cell lung carcinoma.