Of note is the fact that >60% humans naturally exposed to either acute P. falciparum (63%) or P. vivax (67%) malaria infection show IFN-γ responses to PfMSP5, suggesting it is (1) immunogenic in humans, (2) has the potential to be boosted by natural infection, and (3) is potentially a cross-reactive antigen between the two main stains of malaria found in many malaria endemic regions of the globe, including Asia (20). The gene discussed is IFNG; the disease is malaria.