Mitochondrial nicotinamide adenine dinucleotide-dependent deacetylase, Sirtuin-3 (Sirt 3) defect downregulates mtDNA repair gene (8-oxoguanine DNA glycosylase, OGG1-2a), increasing the proliferation of oral cancer, breast cancer, head and neck carcinoma [69, 70]. The gene discussed is SIRT3; the disease is breast cancer.