Bombesin receptors (gastrin-releasing peptide receptors, GRPRs) are G-protein coupled receptors that are highly overexpressed in several human tumors, such as prostate cancer, lung cancer (small-cell and non-small-cell), breast cancer, and renal cancer [158], in line with PSMA are amenable for theranostic use [159]. The gene discussed is FOLH1; the disease is prostate cancer.