To examine the capacity of IL-6 transgenic SPZ to develop into hepatic EEF in vivo and to differentiate into blood stages, C57BL/6 mice were injected i.v. with 104 SPZ of IL-6 Tg-PbANKA/LISP2 line 1, or line 2, or with parental WT (PbGFP) SPZ, as shown in Figure 2C, and parasitemia was followed over time. The gene discussed is IL6; the disease is parasitic infectious disease.