To establish whether resolved IL-6 Tg-PbANKA/LISP2 SPZ-induced parasite infection might confer protection against challenge with heterologous parasites, C57BL/6 mice infected twice with IL-6 Tg-PbANKA/LISP2 SPZ and challenged one month later with WT PbANKA SPZ and which were completely immune to reinfection, were infected 4 months later either with homologous WT PbANKA SPZ or with heterologous nonlethal P. yoelii 17XNL SPZ (Figure 7A). The gene discussed is IL6; the disease is parasitic infectious disease.