A similar observation has been made in P. berghei ANKA-infected mice; animals that were depleted of CD25+ cells prior to infection and drug-cured on day 5 developed significantly stronger IFN-γ memory responses on day 14 than did intact infected/cured mice, and these mice also developed much more severe, and frequently fatal, clinical symptoms upon reinfection, despite more efficient parasite clearance [35]. The gene discussed is IFNG; the disease is infection.