A specific inhibition of cell adhesion by LGRFYAASG-pen was observed in the complete cell panel, and was independent of tumor type (sarcoma, melanoma or carcinoma), species origin (human or murine), and adhesive matrix (fibronectin or vitronectin) (Fig. 3), suggesting an overall impairment of the cytoskeleton. The gene discussed is FN1; the disease is sarcoma.