“…Therefore, compared to other national pediatric oncology groups, the infrastructure for rare tumors in children and adolescents is very well developed in Germany. For many entities, the integration into the network of the GPOH has already been achieved, and reporting of these patients to the GCCR proved to be beneficial [1,3]. Nevertheless, a group of patients with rare tumors remains excluded from the diagnostic, therapeutic, and scientific network of the GPOH so far and the STEP Registry focuses in particular on these non-GPOH trial patients.…”