Fig. 4. Organization of F-actin cytoskeleton in E6 cells. Cells at high (a-d) and low (a'-d') cell densities were stained with rhodamineconjugated phalloidin. (a,a') Neo cells; (b,b') Glu18E6 cells; (c,c') WT18E6 cells; (d,d') Leu18E6 cells. Bar, 40 µm (a-d) and 20 µm (a'-d'). Arrowheads in d' indicate cells that lack actin filaments.