Hypermethylator phenotypes affect both the frequency and density of methylation in AML.

Shown is the mean methylation density of PCR⁺ genes (ie, genes defined as having methylation of 10% or greater) plotted against the number of PCR⁺ genes in a particular patient. The mean methylation density of the methylated genes progressively increases as the number of genes methylated increases, suggesting that both methylation frequency and density are affected in these patients.