293T cells transfected with MUC1 and pEGFP-actin (green) were stimulated with ICAM-1-positive NIH3T3 transfectants and Z-stack confocal images were acquired. Every 10 minutes, the actin cytoskeleton (green) was 3-dimentionally reconstructed and the cell body was manually contoured (yellow line) at each plane in the Z-series. This allowed for calculation of the ratio of actin voxel intensity within the protrusions compared with that in the whole cell providing an accurate numerical representation of the cytoskeletal dynamics. For details see the article by Shen and colleagues on page 555.