Disruption of cell polarity induced by TGF-β1 treatment prevented folding.

<p><i>(A)</i> F-actin (green) and gp135 (red) fluorescence. Cells were treated with TGF-β1 (1.5 ng/ml) for 2 days before fixation. Bar = 25 µm. <i>(B)</i> Time-lapse images of polarity-disrupted epithelial colonies after the gel overlay. Numbers in the images represent the observation time (h). Bar = 100 µm.