Whereas non-treated cells, grown on a fibronectin-coated surface, did not form typical epitheloid morphology but floated in clusters in the medium, anti-CK MAb treated breast tumor cells spread over the fibronectin-coated surface accompanied by rearrangement of the cytoskeleton, as evident by the reorganization of actin in bundles (Figures 2A and 2B). The gene discussed is FN1; the disease is breast neoplasm.