It has been shown that autoimmune B cell activation plays a role in the initiation and propagation of SS by producing abnormal antibodies including interferon (IFN)-γ, IL-4, a B cell activating factor and perpetuating chronic inflammation, and also contributes to the development of B cell lymphoma.[2,13] Our experiments indicated that IFN-γ was expressed on endothelia of capillaries in lacrimal glands with SS, whereas the molecule was expressed on interstitial fibroblastic cells in those with GVHD. This evidence concerns the gene IFNG and graft versus host disease.