Human N-Glycosylase/DNA Lyase(OOG1) is a DNA repair enzyme, which belongs to the type-1 OGG1 family. OOG1 incises DNA at 8-oxoG residues, and excises 7,8-dihydro-8-oxoguanine and 2,6-diamino-4-hydroxy-5-N-methylformamidopyrimidine (FAPY) from damage DNA. It has a β-lyase activity that nicks DNA 3’ to the lesion. OOG1 together with APEX1 is recruited to nuclear speckles in UVA-irradiated cells. The OGG1 gene mutations may be caused Renal cell carcinoma.

Apurinic-Apyrimidinic Endonuclease 1 (APE1) is required for efficient DNA base excision repair. When the DNA glycosylase remove the damaged bases, APE1 cleaves the AP site to allow resynthesis and ligation to complete repair. APE1 stimulates the DNA binding activity of many transcription factors, which participate in cancer promotion and progression. APE1 regulates the redox state of multiple transcription factors, such as c-Jun, c-Fos, NF-kB, p53. APEN is also involved in calcium-dependent down-regulation of PTH expression.