VCAM1 and melanoma: When Vascular Cell Adhesion Molecule (VCAM)-1 (an endothelial ligand of the melanoma cell-expressed α4β1 integrin) was presented on the same nanostructured matrix at densities ranging from 70 to 1145 ligands/μm2 (corresponding lateral distances of 120–30 nm), a density-dependent inhibitory effect on cell spreading and cytoskeletal activation was observed.