We found that the percentage of proliferating B cells following IL-4 and CD40L stimulation increased from 4% to 63% (59% specific proliferation) in the non-lupus control mice, from 8% to 84% (76% specific proliferation) in lupus mice, from 3% to 58% (55% specific proliferation) in lupus mice infected with live malaria parasite and from 7% to 76% (69% specific proliferation) in lupus mice treated with dead malaria parasite (Fig 5A). This evidence concerns the gene IL4 and malaria.