Non-small-cell lung cancer (NSCLC) is one of the most common malignant tumors in a world.Although the development of the surgery and chemical therapy techniques,survival rates in patients with non-small-cell lung cancer has been not improved. Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase and is overexpressed frequently in NSCLC,which is related to tumorigenesis,development,invasion of NSCLC.Thus, EGFR is one of the most promising targets to tumor therapy.Morever,EGFR gene mutation was frequently tested in NSCLC,especially in Asians,females,nonsmokers,and adenocarcinomas.Some studies found that EGFR gene mutation was related to gefitinib therapy sensibility.