VTN and digestive system cancer: We used the pairs (cells PC12 from pheochromocytoma of the rat adrenal medulla / type I collagen) [47] for α1β1, (erythroleukemia cells K562 / fibronectin) [48] for α5β1, (glioblastoma cell variants α6–U87 / laminin 1) [49] for α6β1, or (α6–U87 / vitronectin) for αvβ3 and αvβ5, (human colon adeno–carcinoma clonal cells HT29–D4 / laminin 1) for α6β4, (HT29–D4 / vitronectin) for αvβ5, (HT29–D4 / fibronectin) for αvβ6targeting.