Functional genomics is rapidly progressing towards the elucidation of elements that are crucial for the cis-regulatory control of gene expression, and population-based studies of disease and gene expression traits are yielding widespread evidence of the influence of non-coding variants on trait variance. Recently, genome-wide allele-specific approaches that harness high-throughput sequencing technology have started to allow direct evaluation of how these cis-regulatory polymorphisms control gene expression and affect chromatin states. The emerging data is providing exciting opportunities for comprehensive characterization of the allele-specific events that govern human gene regulation.