Regulation of spreading of PBLs on fibronectin by Vav and Rac. (A) Human PBLs were transfected with the indicated constructions and stained for either Vav (red) or actin (blue). Representative cells are shown. (B) Quantitative analysis of the experiments shown in panel A. More than 50 cells per condition were analyzed with ImageJ for area quantification. Data represent the mean ± SD.