The human neuroblastoma cell line SH-SY5Y was incubated in presence of fluorescent versions of the SI inhibitor, the ANG-SI conjugate and the ANG peptide labeled with the dye TAMRA (5- carboxytetramethylrhodamine) and their internalization was monitored by flow cytometry and confocal microscopy. The gene discussed is ANG; the disease is neuroblastoma.