 on the substrate roughness *in vitro*, as shown by confocal laser-scanning microscopy. ECJ development was followed by immunocytochemical staining for the expression level of E-cadherin (red) at 0, 00, 00, and 00 hours after cell seeding. F-actin (green) was stained with FITC-phalloidin. Nuclei were stained with DAPI (blue). The lower right picture in each set of 0 pictures is a merged image of the E-cadherin, F-actin, and nuclei images. Refer to the results section for details regarding ECJ development (short bar=00 µm