OGG1 and diabetes mellitus: (i) Five studies were review/meta-analysis, (ii) 8 studies were involving only general healthy population, (iii) 18 studies were involving OGG1 mutations in patients other than cancerous, for example, diabetes, cataract, endometriosis, and so forth, (iv) 14 studies used DNA samples from tissues other than blood samples of cancer patients, and (v) 45 studies were older than January 2007.