CD4 and infection: Although Nfkbid promotes T cell production of IFNγ and IL-2 in in vitro stimulation assays [39] and promotes thymic development of FOXP3+ T regulatory cells [40], no impairment of T cell cytokine production was observed, nor were frequencies of FOXP3+ CD25hi CD4+ T regulatory cells altered in bumble compared to wildtype mice during chronic and secondary infection (S4 Fig).