ADH5 and chronic hepatitis B virus infection: Particularly, GSNOR deficiency, or somatic loss-of-function mutations (e.g., deletion) in GSNOR gene, which have been found being associated with many cases of hepatic cirrhosis and chronic hepatitis B or C, induces S-nitrosylation of the DNA repair system member O6-alkylguanine-DNA alkyltransferase (AGT).