Accumulative data showed that pathogenic CD4+ T cells are recognized as critical contributors to the development of Behcet's disease and VKH syndrome as evidenced by the aberrant production of Th1, Th2, Th17 and Treg cytokines and the aberrant frequency of these four T cell subsets11, 12, 13, 14, 15, 16, 17, 18, 19. The gene discussed is CD4; the disease is Behcet disease.