Packaging the 3 billion nucleotides of the human genome into the nucleus of a cell requires tremendous compaction. To accomplish this feat, DNA in our chromosomes is wrapped around spools of proteins called histones to form dense repeating protein/DNA polymers known as chromatin: the defining template for gene regulation. Far from serving as mere packaging modules, chromatin templates form the basis of a newly appreciated and fundamentally important set of gene control mechanisms termed epigenetic regulation. By conferring a wide range of specific chemical modifications to histones and DNA, epigenetic regulators modulate the structure, function, and accessibility of our genome, thereby exerting a tremendous impact on gene expression. Hundreds of epigenetic effectors have recently been identified, many of which are chromatin-binding proteins or chromatin-modifying enzymes. Significantly, an increasing number of these proteins have been associated with a variety of disorders such as neurodegenerative disorders, metabolic diseases, inflammation, and cancer. Thus, highly selective therapeutic agents directed against this emerging class of gene regulatory proteins promise new approaches to the treatment of human diseases.