First imaging and biodistribution studies using SPECT/CT and radiolabeled high-affinity camelid single-domain antibody (nanobody) directed specifically against human DPP6, allowed to visualize transplanted DPP6-expressing Kelly neuroblastoma cells or insulin-producing human EndoC-βH1 cells in immunodeficient mice. This evidence concerns the gene DPP6 and neuroblastoma.