Fluorescence microscopy studies using highly (A-673, rhabdomyosarcoma) and moderate (HT-1080, fibrosarcoma) MMP-2 expressing cell lines showed efficient binding of 48 to the MMP-2 positive cells while no binding to MMP-2 negative cells (MCF-7, breast cancer cells). The gene discussed is MMP2; the disease is rhabdomyosarcoma.