They differentiate into inflammatory macrophages and dendritic cells (DCs) that produce tumor necrosis factor (TNF), inducible nitric oxide synthase, and reactive oxygen species in response to bacterial and parasitic infection (Narni-Mancinelli et al., 2011; Robben et al., 2005; Serbina and Pamer, 2006; Serbina et al., 2003b) and can stimulate naive T cells (Geissmann et al., 2003; Serbina et al., 2003a). Here, TNF is linked to parasitic infectious disease.