(A) Shear test measuring cell sheet cohesion shows significant diminishment in cohesion strength with disruption of each component of the cytoskeleton using toxins, with acrylamide treatment exhibiting the greatest decrease in cell sheet cohesion. *p<0.05 compared to the matched untreated control. Unnormalized times in seconds: con/CytD=140/73; con/noco=93/40; con/acryl=148/45. (B) Shear test shows double siRNA knockdown of keratin 5 and keratin 14 weakens cell sheet cohesion. *p<0.05 and **p<0.01. Unnormalized times in seconds: control=145; negative control=150; K5=113; K14=98; K5+K14=45. (C) Immuno-staining and (D) western blot analysis of siRNA transfection on adhered cells demonstrates reduction of K5 or K14 expression levels. K5/K14 knockdown together significantly reduced both K5 and K14 expression levels. Scale bar is 10 μm. GAPDH was used as a loading control.