||P.26 right column bottom paragraph: "There are approximately 30 million CpG dinucleotides in the human genome, constituting about 1% of total nucleotide content. A fraction of these CpGs, 1–2%, are clustered in highly dense areas known as CpG islands (CGIs), while the majority of CpGs are dispersed sparsely throughout the genome. A CGI is defined as a region greater than 500 bps with more than 50% CpG content [BNID 113103]. More than half of all CGIs are associated with coding gene promoters, directly regulating gene expression by determining whether or not the basal transcriptional machinery can bind. The vast majority of the genome is highly methylated, which promotes genomic stability by limiting the activity of transposable elements, while certain regulatory elements, including CGIs and enhancers, are usually lowly methylated [ref 28], [ref 29] and [ref 30]."