Resistance to infection is dependent on an effective control of Listeria and requires the production of various cytokines and immune mediators including IFN-γ, TNF, IL-2, IL-6, IL-17, and the NOX2 (gp91phox, nicotine adenine dinucleotide phosphate oxidase)-dependent production of reactive oxygen species (ROS) [3]–[10], whereas IL-4 is associated with disease progression [11]. The gene discussed is IFNG; the disease is infection.