d,l-α-difluoromethylornithine (DFMO), a suicide inhibitor of ornithine decarboxylase (ODC), the enzyme that converts ornithine to putrescine, has shown remarkable therapeutic efficacy in treating African sleeping sickness caused by Trypanosoma brucei gambiense (6, –, 9). The gene discussed is ODC1; the disease is human African trypanosomiasis.