IFNG and chlamydia infectious disease: Interestingly, in a mouse model of C. trachomatis genital tract infection, two studies have found that a subset of CD4 or CD8 cell populations can produce both IFN-γ and IL-13 (termed CD4γ13 or CD8γ13 T cells, respectively); adoptive transfer of either Chlamydia-specific CD4γ13 or CD8γ13 T cells protects oviducts from immunopathology, suggesting a protective role of IL-13 during Chlamydia infection (146, 147).