DNA methylation is an epigenome mark involved in key biological processes (Bird et al., 1986; Bird et al., 2002; Ziller et al., 2013), such as embryonic development, transcription, genomic imprinting, learning, memory or age-related cognitive decline (Schubeler et al., 2012; Oliveira et al., 2012; Zovkic et al., 2013; Lister et al., 2013). DNA methylation plays an important role in the origin and function of CpG islands (CGIs). Aberrant methylation (mostly hypermethylation) of CGIs has been implicated in the appearance of several disorders, such as cancer, immunodeficiency or centromere instability (Baylin et al., 2001; De Smet et al., 1999; Esteller et al., 2001; Issa et al., 2004; Riazalhosseini et al., 2008; Krebs et al., 2012; Wasserkort et al., 2013).
(Bird et al., 1986) CpG-rich islands and the function of DNA methylation. Nature.
(Bird et al., 2002) DNA methylation patterns and epigenetic memory. Genes Dev.
(Ziller et al., 2013) Charting a dynamic DNA methylation landscape of the human genome. Nature.
(Schubeler et al., 2012) Epigenetic islands in a genetic ocean. Science.
(Oliveira et al., 2012) Rescue of aging-associated decline in Dnmt3a2 expression restores cognitive abilities. Nat Neurosci.
(Zovkic et al., 2013) Epigenetic regulation of memory formation and maintenance. Learn Mem.
(Lister et al., 2013) Global epigenomic reconfiguration during mammalian brain development. Science.
(Baylin et al., 2001) Aberrant patterns of DNA methylation, chromatin formation and gene expression in cancer. Hum Mol Genet.
(De Smet et al., 1999) DNA methylation is the primary silencing mechanism for a set of germ line- and tumor-specific genes with a CpG-rich promoter. Mol Cell Biol.
(Esteller et al., 2001) A gene hypermethylation profile of human cancer. Cancer Res.
(Issa et al., 2004) CpG island methylator phenotype in cancer. Nat Rev Cancer.
(Riazalhosseini et al., 2008) Do we use the appropriate controls for the identification of informative methylation markers for early cancer detection? Genome Biol.
(Krebs et al., 2012) Tracking the evolution of cancer methylomes. Nat Genet.
(Wasserkort et al., 2013) Aberrant septin 9 DNA methylation in colorectal cancer is restricted to a single CpG island. BMC Cancer.
(Geisen et al., 2014) NGSmethDB: an updated genome resource for high quality, single-cytosine resolution methylomes. Nucleic Acids Res.