Strikingly, this unbiased analysis identified effector cells as CD62LloIL-7Rα− during the acute parasitemia at day 9, while memory cells were easily distinguished by their upregulation of IL-7Rα, as seen in the majority of divided, CFSEneg B5 Tg cells by day 60, which fell into both the effector (Tem) and central (Tcm) memory categories as indicated by their expression of CD62L. The gene discussed is SELL; the disease is parasitic infectious disease.