IL33 and malaria: To determine whether IL-33 could modulate malaria pathogenesis, we first infected C57BL/6 mice with Plasmodium berghei ANKA (PbA) parasites (104 parasitized red blood cells, pRBC) and treated the mice with recombinant murine IL-33 (0.2 μg/mouse/day, intraperitoneally) starting from day 0.