Previously, several studies identified KLF6 as a tumor-suppressor gene due to frequent somatic inactivation of the KLF6 gene and/or downregulation of KLF6 expression in prostate carcinoma, glioblastoma, colorectal tumors, gastric cancer, hepatocellular carcinoma, and lung cancer [10,11,17,27,28,29]. The gene discussed is KLF6; the disease is lung cancer.