The present study demonstrated that KLF17 suppressed the invasion of lung adenocarcinoma cells, and the anti-invasion effects of KLF17 on cancer cells were caused partially by inhibiting the expression of uPA, which has been reported to be involved in crucial cellular functions of invasion and metastasis of breast cancer, ovarian cancer, gastric cancer, esophageal cancer, lung cancer, liver cancer, colon cancer, prostate cancer and bile duct cancer [11–17]. This evidence concerns the gene PLAU and gastric cancer.