MDA-MB-231 cell labeled with (red) CellMask and embedded in (green) fluorescently labeled collagen I imaged starting at t = 5.75 h after cells were embedded in collagen. The cell shows the strongest collagen reorganization at the site of polarized, recurrent clustered blebs. Images were taken every 9.7 seconds. Length of movie is 30 minutes. Movie is played back at 7 frames/s. Frames from this movie are also shown in Fig. 8C,D in the main text. Scale bar = 10 μm.