CLIP-170 moves towards the peripheral ring of F-actin in B cells spreading on immobilized anti-Ig. A20 cells were transfected with CLIP-170-GFP (green) to mark the plus ends of microtubules, and with LifeAct-mCherry (red) to visualize F-actin. The cells were allowed to spread on anti-IgG-coated coverslips for 10 min and were then imaged for 2.25 min using a spinning disk confocal microscope. Images were acquired every 0.9 sec. The video is played back at 10 frames per second (8X real time).