RTN4R and neoplasm: To assess the suitability of the newly constructed internalizing NGR (iNGR) peptide—that contains a target specific NGR motif and a tumor-penetrating CendR sequence (C-end rule peptide; R/KXXR/K)—for the imaging of APN/CD13 overexpressing tumours, Zhao et al. carried out the comparative performance evaluation of [68Ga]Ga-labelled iNGR and NGR (demonstrated in Table 1) [43].