On the other hand, the failure of all assays to detect the sole DENV-4 was probably due to chance, as this patient had secondary dengue (with low IgM level) on 5th day of illness, when the level of free and detectable IgG and NS1 happened to be too low after their union in vivo [23, 45, 47, 48]. Here, CD40LG is linked to dengue disease.