Difluoromethylornithine (DFMO) exhibits anti-parasitic, anti-angiogenic, anti-metastatic, anticancer chemotherapeutic, and chemopreventive activities. DFMO inhibits ornithine decarboxylase, suppressing polyamine and thymidine synthesis. DFMO inhibits growth of Leishmania and Trypanosoma and is clinically used to treat African sleeping sickness. This compound suppresses breast cancer cell invasion by increasing PKA signaling and inhibits neovascularization in animal models. In other animal models, DFMO decreases the epithelial-to-mesenchymal transition (EMT), suppressing squamous cell carcinoma tumor growth; it also limits the development of esophageal tumors in vivo.