iRGD peptide 1 (iRGD) inhibits migration of tumor cells and caused chemorepulsion in vitro in a CendR- and NRP-1-dependent manner. iRGD peptide 1 induces dramatic collapse of cellular processes and partial cell detachment, resulting in the repellent activity. These effects are prominently displayed when the cells are seeded on fibronectin, suggesting a role of CendR in functional regulation of integrins.