Representative images showing the morphology of ME180 cells with or without TGF-α (10 ng/ml) treatment for 24 h (scale bar: 50 μm) or 108 h (scale bar: 25 μm). Please note the elongation of ME180 cells after TGF-α treatment for 24 h (TGF-α, 24 h) and the formation of multiple layers in ME180 cells after TGF-α treatment for 108 h (TGF-α, 108 h). 