Two classes of enhancers defined by the presence and absence of H3K4me1 in their histone states and their DNA methylation levels. A) DNA methylation profiles of two bicluster classes and random genomic loci. Inset, median expression levels of genes next to enhancers of the two classes. P-value is based on one-tailed t-test. B) Correlation between bicluster DNA methylation level and expression level of nearby genes.