GRPR and neoplasm: There was one case with only integrin αvβ3 positive expression (GRPR negative), the T/N ratio of 99mTc-3P4-RGD2 imaging was higher than that of 99mTc-RGD-BBN imaging (2.56 vs. 2.45), which might have resulted from the improved in tumor affinity and pharmacokinetic of dimeric RGD peptide over monomeric RGD.