Figure 1

The cytosine methylation and active demethylation pathway. (DNMT4: DNA methyltransferase, TETs: ten eleven translocation enzymes, AID: activation-induced cytosine deaminase, APOBEC: apolipoprotein B mRNA editing enzyme, TDG: thymine DNA glycosylase, SMUG1: single-strand-selective monofunctional uracil-DNA glycosylase 1, UNG: uracil-DNA glycosylase, MBD4: methyl-CpG-binding ___domain protein 4, BER: base excision repair). Reprinted from Biochimica et Biophysica Acta—Reviews on Cancer, 1869 (1), Olinski R, Gackowski D, Cooke M. Endogenously generated DNA nucleobase modifications source, and significance as possible biomarkers of malignant transformation risk, and role in anticancer therapy, 29–41 (2018), with permission from Elsevier.