DNA methylation (high left corner – blue characters) and DNA demethylation (active - red italic characters; passive - green characters) pathways. See text for details.
SAM: S-Adenosyl methionine; SAH: S-adenosylhomocysteine; DNMT: DNA methyltransferase; AID: activation-induced deaminase
APOBEC: apolipoprotein B mRNA-editing enzyme complex; TDG: thymine-DNA glycosylase; BER: Base excision repair