Lymphoid enhancer-binding factor 1 (LEF1) is a key downstream mediator of the activated Wnt/ β-catenin signaling pathway, which regulates tumorigenesis and the progression of multiple tumours, such as breast cancer, lung adenocarcinoma, colon cancer, prostate cancer and leukemia 5-9. The gene discussed is LEF1; the disease is lung adenocarcinoma.