It has recently been shown that G strain extracellular amastigotes do not give rise to patent parasitemia in mice, possibly due to their susceptibility to interferon-gamma [35) In this study, bloodstream parasitemia was not detected in animals infected with G strain EAs either overexpressing pTREX-δ-Amastin-GFP or pTREX-GFP. The gene discussed is IFNG; the disease is parasitic infectious disease.