?-difluoromethylornithine African sleeping sickness B-lymphocytes CRISPR DFMO Drosophila imaginal discs M2 macrophages MCF-7 cells MYC NF-?B Snyder-Robinson Syndrome Streptococcus pneumoniae T-lymphocytes X-linked intellectual disability aging airway smooth muscle cells antizyme antizyme 1 antizyme inhibitors atrophy autoimmunity autophagy bis(ethyl)polyamine analogs breast cancer cadaverine cancer capsule carcinogenesis cell differentiation chemoprevention