Other studies have indicated that filter papers should be stored in a refrigerator but that this does not completely prevent a decline of antibody concentrations[9,10] It was also shown that in particular the anti-dengue IgM in filter paper blood spots from secondary cases decreased significantly on storage[10] In this study filter papers were not stored in a refrigerator but in an air-conditioned room. The gene discussed is CD40LG; the disease is dengue disease.