IFNG and vitiligo: However, our study did not find a significant difference in plasma IFN-γ levels between patients with active and stable vitiligo, though the level of plasma IFN-γ was increased in vitiligo patients, which possibly due to differences in the definitions of active and stable vitiligo, their active vitiligo definition: patients experienced progression within 3 months; our active vitiligo definition: patients experienced progression within 6 months.