Abstract: Compounds having a zinc-binding moiety, such as, for example, a hydroxamic acid group, can inhibit histone deacetylase. Histone deacetylase inhibition can repress gene expression, including expression of genes related to tumor suppression. Inhibition of histone deacetylase can lead to the histone deacetylase-mediated transcriptional repression of tumor suppressor genes. For example, inhibition of histone deacetylase can provide an alternate route for treating cancer, hematological disorders, such as hematopoiesis, and genetic related metabolic disorders, such as, cystic fibrosis and adrenoleukodystrophy.