TNF and malaria: In vitro stimulation of whole blood and PBMCs isolated from malaria naïve individuals is the most direct test for an innate immune response and demonstrates that high concentrations of P. falciparum schizont-stage parasites (2,000/μL) stimulate production of TNFα, IL-8, IL-1β, IL-6, IFNγ and GM-CSF within 6 hours [44,49].