Regarding a possible function of PA28γ in innate immunity and host defense against infections by bacterial pathogens, a positive correlation between PA28γ levels and resistance to infection of Staphylococcus aureus [138] and Listeria monocytogenes has been reported [139], which in both cases is attributable to regulatory activity on the NF-kB pathway in macrophages. Here, PSME3 is linked to infection.