Therefore, KLF4 can be used as a negative regulator of cancer stem cells in lung cancer, and it is also consistent with the result of knocking down MACC1 to inhibit the dedifferentiation of non-CSCs in lung cancer by up-regulating the expression of KLF4 (Figs. 4, 5 and Fig. S3). This evidence concerns the gene MACC1 and cancer.