IFNG and parasitic infectious disease: Wild type (WT) or IFN-γ KO (IFN-γ KO) BALB/c mice were immunized twice, intradermally, 2 weeks apart, with PSNPs-MSP4/5 and 2 weeks following the last immunization, mice were challenged with P. yoelii parasites and monitored for survival and parasitemia levels.