Abstract: The present invention relates to a cyclopeptide characterized in that it comprises the YSNS amino acid sequence, and more particularly a cyclopentapeptide which forms a ?-bend structure at the YSNS amino acids. In one specific embodiment, the cyclopeptide of the invention is capable of binding to the ?V?3-integrin. The application also claims the use of a cyclopeptide of the invention in the treatment of cancer, and more particularly in the treatment of the various forms of melanoma, and also in the manufacture of a medicament for treating cancer. Finally, the application describes the use of a cyclopeptide of the invention for inhibiting or reducing angiogenesis, and more particularly in tumours, and also in the manufacture of a medicament for inhibiting or reducing angiogenesis.