Inhibition of cell spreading can sensitize metastatic tumor cells to TRAIL-induced apoptosis in vitro. The image shows GFP-positive (green) MDA-MB-231 human breast cancer cells that have been stained for actin with phalloidin (red) and nuclear stained with DAPI (blue). These cells have been treated with a b1 integrin blocking antibody before seeding onto collagen I, resulting in marked spreading defects accompanied by an increased sensitivity to TRAIL-induced apoptosis. Inhibition of other members of the integrin signalling pathway also resulted in increased TRAIL sensitivity. For further details, please see article by Phipps and coworkers on page 249 in this issue.