Although concluding whether CD8+ CTL hyperactivity is a cause or a consequence of the quantitative and functional defects of Tregs requires further investigation, we hypothesize that deficiencies and dysfunction in the Treg population fail to maintain peripheral tolerance and lead to a copious expansion and activation of self-reactive CD8+ CTLs, which destroys melanocytes and leads to a high frequency of generalized autoimmune diseases in GV patients. This evidence concerns the gene CD8A and autoimmune disease.