CTLA4 and primary adrenal insufficiency: Since the rediscovery of T reg cells, the immuno-regulatory role of protein in the immune responses and the importance of its deregulation in autoimmune diseases have been well established.[27–30] A large body of information exists on the association of CTLA-4 gene polymorphisms and various autoimmune diseases such as Graves' hyperthyroidism, Addison's disease, etc.[31, 32] Lack of association between CTLA-4 gene polymorphism and vitiligo might therefore suggest the involvement of other immune regulatory genes and/or reflect a different nature or multiple etiologies for vitiligo.