For diagnostic purposes, in areas with transmission of JE and dengue viruses, anti-dengue virus IgM testing should routinely be conducted on serum samples with JE IgM antibody.22 In addition, WHO laboratory guidance recommends confirmatory testing on receipt of a positive JE IgM antibody result in various situations, and the WHO has designated several laboratories within its JE laboratory network as reference laboratories to provide such testing.24,25. The gene discussed is CD40LG; the disease is Japanese encephalitis.