99mTc-RTD-Lys-(Arg11)CCMSH, 99mTc-RVD-Lys-(Arg11)CCMSH and 99mTc-RSD-Lys-(Arg11)CCMSH exhibited comparably high receptor-mediated B16/F1 melanoma uptake to 99mTc-RAD-Lys-(Arg11)CCMSH. This evidence concerns the gene RRAD and melanoma.