The tumor uptake at ~2 h reported in our study (8.47 ± 0.46%ID/g and 6.90 ± 0.81%ID/g for probe [111In]In-12 and [111In]In-15, respectively) was higher than the value that Zhang et al. obtained at ~1 h (5.50 ± 1.03%ID/g) for their GRPR-directed dual-modality probe, based on the RM2 backbone. This evidence concerns the gene GRPR and neoplasm.