Cells lacking RSFs generate large traction stresses. (A) Images of GFP-actin (top row) and heat map of traction stress magnitude (bottom row) of WT, Dia Inh, and Atn-1 KD U2OS cells plated on fibronectin-coated PAA gels. For traction stress images, the white line indicates the cell outline, and the heat scale of traction stress (in Pa) is indicated at the bottom right. Bar, 10 µm. (B) Plot of the total traction force exerted by WT, Dia-inhibited, Dia1 siRNA, and Atn-1 KD U2OS cells (error bars indicate SEM; n = 18, 14, 11, and 24 cells for each condition, respectively; *, P < 0.05; **, P < 0.01; ***, P < 0.001 with respect to WT).