For example, in cancersoverexpressing SIRT3, like head and neck squamous cell carcinoma (HNSCC),SIRT3 keeps the ROS species at an adequate rather low level, resultingin a malignant phenotype.76 In HeLa cells,SIRT3 removes acetyl groups from Ku70, leading to increased Ku70-Baxinteractions and subsequently facilitating the movement of Bax tothe mitochondria, thus leading to cancer cell survival through protectionfrom genotoxic and oxidative stress.77 Here, XRCC6 is linked to head and neck squamous cell carcinoma.