IFNG and systemic lupus erythematosus: Indeed, a majority of such pathogenic Th clones produced IL-2 and IFN-γ in response to nucleosomes that contain histone peptides bearing cationic determinants, and nucleosome-specific T cells are detectable in pre-clinical stage lupus-prone mice before pathogenic autoantibodies are detectable in their serum (56, 60, 61).