ODC1 and neuroblastoma: There has been long-standing interest in targeting polyamines as a therapeutic approach for cancer,21,22 and studies using oral difluoromethylornithine (DFMO), which inhibits polyamine synthesis by irreversibly inhibiting ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis, have shown some success.22, 23, 24 Most recently, an analysis of patients with high-risk neuroblastoma (HRNB), who received up to 2 years of treatment with oral DFMO after completion of immunotherapy, showed significant improvement in both event-free survival and overall survival.25