Final linear regression models that comprised IL-4, TGF-β, IL-10 or IL-10/TNF-α or IL-10/IFNγ ratio and sTNFRII or sTNFRII/TNF-α ratio as independent variables, in addition to age, gender and length of exposure to malaria, pointed to the length of exposure to malaria (β = −0.330, P = 0.002), TGF-β levels (β = −0.323, P = 0.003), and the IL-10/TNF-α ratio (β = 0.332, P = 0.004) as major independent predictors of P. vivax parasitemias. The gene discussed is IFNG; the disease is malaria.