When DNA undergoes oxidative damage, two of the most common damages change guanine to 8-hydroxyguanine or to 2,6-diamino-4-hydroxy-5-formamidopyrimidine.
<a href="//commons.wikimedia.org/wiki/User:Chaya5260" title="User:Chaya5260">Chaya5260</a>, Armenian translation by user:GgGevorg
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<a href="//commons.wikimedia.org/wiki/File:Guanine_and_2_oxidative_products.svg" title="File:Guanine and 2 oxidative products.svg">File:Guanine and 2 oxidative products.svg</a>