 This is a double blind, placebo controlled study of 52 patients who are at least one-year post-solid organ transplant. Subjects will receive either 12 months of DFMO or a placebo. The specific aims are to determine if DFMO at 500 mg daily will be well tolerated for 12 months and not affect organ transplant viability; will inhibit 12-O-tetradecanoylphorbol-13-acetate TPA-induced ornithine decarboxylase ODC in skin biopsies by approximately 50 for the 12 months of therapy; and will be able to decrease polyamine levels in skin biopsies for the 12 months of treatment. 