Peak calling is a computational method used to identify areas in a genome that have been enriched with aligned reads as a consequence of performing a ChIP-sequencing or MeDIP-seq experiment. These areas are those where a protein interacts with DNA. When the protein is a transcription factor, the enriched area is its transcription factor binding site (TFBS). Popular software programs include MACS. Wilbanks and colleagues is a survey of the ChIP-seq peak callers, and Bailey et al. is a description of practical guidelines for peak calling in ChIP-seq data.