Table 2. Development of ECJs of HOK-16B cells depending on the substrate roughness in vitro .

Roughness	ECJs/total CCJa)
	Mean	SD	Median
Smooth	0.769	0.210	0.855b)
R(4000)	0.670	0.254	0.760b)
R(1200)	0.356	0.202	0.304c)
R(200)	0.219	0.115	0.214d)

Data were analyzed using Kruskal-Wallis test (P=0.001). Pairwise comparisons were then performed using Mann-Whitney test for post hoc multiple comparison at Bonferroni-adjusted alpha value (0.05/6=0.0083) (n=30).

ECJs: E-cadherin junctions, CCJ: cell-cell junction, SD: standard deviation, Smooth: smooth culture dish, R(4000): prepared with #4000 sandpaper, R(1200): prepared with #1200 sandpaper, R(200): prepared with #200 sandpaper.

^a)Quantitative ECJs developmental value was obtained by dividing the length of ECJs by the length of total CCJ per cell; ^b,c,d)A different group from other 2 groups (P<0.001) according to Mann-Whitney test for post hoc multiple comparison at Bonferroni-adjusted alpha value (0.05/6=0.0083). There is no significant difference between smooth and R(4000) (P=0.128).