Plaque Reduction Neutralization Tests (PRNTs) that detect specific neutralizing antibodies against DENV and other flavivirus are performed on IgM positive patients to determine the cause of infection or to rule out other flavivirus, such as ZIKV, YFV and, in some cases, to determine the infecting DENV serotypes [5, 122]. The gene discussed is CD40LG; the disease is infection.