VDR and Behcet disease: VDR gene polymorphisms have been implicated in mediating susceptibility to many autoimmune and autoinflammatory diseases.11, 19, 21, 22, 23 The most studied VDR polymorphisms are TaqI, BsmI, ApaI, and FokI.14, 16 Kolahi et al.11 showed the association between FokI polymorphism of VDR and BD in the Azari population of Iran.