(A) When overexpressing TMEM17 in H1299 and SPC cells, Snail was downregulated, Occludin and Zo-1 were upregulated. When depleting TMEM17 in A549 and LK2 cells, Snail expression was upregulated and Occludin and Zo-1 were downregulated. (B) TMEM17 overexpression downregulated the levels of p-ERK and its downstream factor p-P90RSK, and their expression were increased after knockdown TMEM17. (C) Western blotting examination of p-ERK, p-p90RSK, Snail, Occludin and Zo-1protein levels after transfecting TMEM17-siRNA with or without incorporation of PD98059. Representative images of cells on the bottom of Transwell membranes show the changes in invasive cell numbers (×200, scale bar= 50 μm) (*P< 0.05). T17 was short for TMEM17