Infections with the filarial nematodes Wuchereria bancrofti, Brugia malayi, and M. perstans typically reduce immunity to malaria parasites and other pathogens, with an IL-10-dependent decrease in IL-12p70, interferon (IFN)-γ and IFN-γ-induced protein 10 (IP-10) responses upon T-cell stimulation [11–14]. Here, IL10 is linked to infection.