To determine the distribution of the FITC-conjugated CPE peptide in tumor bearing animals and whether FITC-conjugated CPE peptide is able to localize to tumor cells in vivo, SCID mice harboring OSPC-ARK-1-derived tumor xenografts 6-weeks after tumor implantation were injected via the tail vein (i.v.)with FITC-conjugated CPE peptide (100 μg). The gene discussed is CPE; the disease is neoplasm.