EGFR and cancer: In this study, we planned to extract DNA from cancer tissue and corresponding peripheral blood cell from patients with EGJ cancer, then perform DNA sequencing of EGFR-TK domain including exons 18, 19, 20 and 21 in order to assess the EGFR mutation in carcinoma cell initially and predict the therapeutic effect of small molecule inhibitor of gefitinib on EGJ cancer.