In vitro IC50 (nM) values of the peptides against αvβ3, αvβ5, α5β1 and αIIbβ3 integrins determined from competitive ELISAs. The efficacy (in cellulo IC50 in nM) was determined from the competitive cell-adhesion to vitronectin with αvβ5 expressing MDA-MB-231 breast cancer cells and αvβ3, αvβ5 and α5β1 expressing U-87 MG glioblastoma cells. MCF7 breast cancer cells were taken as negative control in the cell-adhesion assay, where the IC50 for all the analogs was in the high μM range (data not shown). n = 5 ± SEM. This evidence concerns the gene VTN and glioblastoma.