ound an octameric structure formed by core histones. Repeating nucleosomes assemble into higher-order structures stabilized by a linker histone. Chromatin modification involves the methylation of cytosine residues in DNA and the many ways in which the histone residues are modified. Histone modifications mostly targets the histone tails which extend from the core fold of the nucleosome and thus, are accessible for modifications and interactions. The modification pathways bring together the enzymes that catalyze the modification and those that catalyze its removal or change, known as 'writers' and 'erasers', respectively, the proteins whose particular domains recognize the modification, known as the 'readers' and the various other interactors or regulators. The remodeling of chromatin involves the ATP-dependent sliding, spacing and repositioning of entire nucleosomes, insertion, eviction or exchange of histones, chromatin assembly and disassembly. It is carried out by four major protein complexes representing four remodeling pathways with distinct functions. Epigenetic changes are heritable and independent of DNA sequence. However, DNA sequence variation can affect the function of players involved and thus, of epigenetic outcomes. An intimate dialog exists between the pathways of chromatin modification and remodeling to finely tune the epigenetic responses. Details are provided in the individual pathway diagram pages that can be accessed from the entries in this page via the Ontology Browser, or directly from the list of interactive pages....(less)