OGG1, also known as 8-oxoguanine glycosylase, is a DNA glycosylase enzyme involved in base excision repair. This protein is the primary enzyme responsible for the excision of 7,8-dihydro-8-oxoguanine (8- oxoG), a mutagenic base byproduct which occurs as a result of exposure to reactive oxygen species (ROS). It has a beta lyase activity that nicks DNA 3' to the lesion.