Cytoplasmic accumulation of Cx26 has been associated with lung metastasis in colorectal cancer36 and with poor prognosis in NSCLC and breast carcinoma.22, 37 Actually, in the present study, we found that overexpression of chimeric Cx26, which resulted in a significantly increase of Cx26 in the cytoplasm of HCC827 and PC9 cells, was sufficient to induce EMT phenotypes and gefitinib insensitivity in vitro and in vivo. This evidence concerns the gene GJB2 and breast carcinoma.