Epigenenetic information can be used to predict if a nucleosome is likely to contain H2A.Z. A. Histone post-translational modifications neighbouring randomly selected genomic regions where a H2A.Z- or H2A-containing nucleosome was found. Red indicates presence of a modification and green indicates absence. B. Accuracies of classifiers trained on a single post-translational modification using the C4.5 algorithm. Post-translational modifications vary greatly in their potential to predict the H2A.Z status of a nucleosome. Most of the best modifications are acetylations. C. Accuracies of the best classifier trained on a combination of the specified number of post-translational modifications. Using multiple post-translational modifications improves the overall classification accuracy. D. Best decision tree inferred using the C4.5 algorithm using four post-translational modifications. Three modifications in this tree (H3K18ac, H4K5ac and H4K8ac), if present in a particular genomic region, guide the classification toward H2A.Z, while the other (H4K20me1) guides it toward H2A.