CD40LG and malaria: A routine laboratory tests diagnosis for fever of undeterminated origin was performed: complete blood count, routine blood chemistry determinations, chest radiograph, erythrocyte sedimentation rate, antinuclear antibodies, rheumatoid factor, blood and urine cultures, Cytomegalovirus IgM antibodies, heterophile antibody, Human immunodeficiency virus antibodies, tuberculin skin test, and, considering the presented fever pattern, blood films, RTC and PCR were requested to exclude the possibility of malaria in the individual.