A/G-specific adenine DNA glycosylase (UniProt Q9UIF7; also known as hMYH, MutY homolog) is encoded by the MUTYH (also known as MYH) gene (Gene ID 4595) in human. Base excision repair (BER) is initiated by damage-specific DNA glycosylases that recognize and remove aberrant bases by hydrolyzing the N-glycosidic bond, creating an apurinic/apyrimidinic (AP) site. This is followed by an (AP)-endonuclease-catalyzed DNA strand incision 5′ to the AP site, trimming of the 5′ end by an (AP)-lyase or an endonuclease, DNA resynthesis by a DNA polymerase and strand sealing by a DNA ligase. Monofunctional glycosylases have only glycosylase activity, whereas bifunctional glycosylases possess additional AP lyase activity and can therefore convert a base lesion into a single-strand break without the need for a separate AP endonuclease. MUTYH/MYH is a monofunctional DNA glycosylase that excises mismatched adenine opposite 7, 8-dihydro-8-oxoguanine (8-oxoG), which is the major mutagenic lesion induced by oxidative stress. Biallelic mutations in MUTYH are associated with MUTYH-Associated polyposis (MAP) and increased risk in colorectal cancer (CRC).