TLR4 and malaria: Several studies report that IFN-γ derived from innate immune cells enhances protective antiparasitic Th1 responses and malaria protection after use of adjuvant AS01 (containing two immunostimulants (TLR4 ligand 3-O-desacyl-4′-monophosphoryl lipid A (MPL) and the purified saponin QS-21) in a liposome-based formulation) or AS03 (containing α-tocopherol and squalene in an oil-in-water (o/w) emulsion).