We were further interested to explore the theragnostic potential of NeoBOMB1 in GRPR-positive mammary carcinoma, by first studying [67Ga]NeoBOMB1 in breast cancer models; Methods: We investigated the profile of [67Ga]NeoBOMB1, a [68Ga]NeoBOMB1 surrogate, in GRPR-expressing T-47D cells and animal models; Results: NeoBOMB1 (IC50s of 2.2 ± 0.2 nM) and [natGa]NeoBOMB1 (IC50s of 2.5 ± 0.2 nM) exhibited high affinity for the GRPR. Here, GRPR is linked to breast cancer.