IFNG and infection: In support of the LEW and F344 rats’ known genetic differences in hypothalamic-pituitary-adrenal axis activity, inflammatory responses, and susceptibility to various infections, autoimmune disorders, and tumors [41–43], the low corticosterone/high pro-inflammatory irradiated LEW rats displayed a 3.18 fold increase in IFN-γ, whereas the high corticosterone/low pro-inflammatory irradiated F344 rats displayed a 40% decrease in IFN-γ that approached significance (p = 0.07).