According to previous reports, IFN-γ and IFN-γ-producing cells are implicated in the pathogenesis of a range of ocular surface diseases including DED [7, 8, 13], ocular Sjögren’s syndrome [3, 9, 10], ocular GVHD [12, 14], corneal allograft rejection [17, 18, 30, 31], and infection with HSV or pseudomonas [32–34]. Here, IFNG is linked to infection.