Expression of NK4 inhibits expression of CSC markers. Cells were mock-infected or infected with Ad-LacZ or Ad-NK4. After incubating for 30 hours, the cells were treated with HGF (10 ng/ml) for 30 min followed by immunoblot analysis. Expression of NK4 protein did not have any effect on the level of total Met and AKT proteins, but P-Met and P-AKT were markedly reduced. In contrast, it modestly reduced P-ERK2, but not P-ERK1. Expression of NK4 also inhibited the active form, but not the total protein, of β-catenin. In addition, Ad-NK4 reduced expression of Oct4 in both Hmeso and Meso 10 cells while Myc was suppressed only in Hmeso.