Various lines of evidence support the association of ADE with severe dengue, including increased incidence of severe dengue in infants born to dengue-immune mothers (12–14); increased viremia in interferon receptor-deficient mice or non-human primates passively immunized with anti-DENV antibodies (15, 16); increased incidence of severe dengue during the second of sequential heterologous DENV outbreaks; and in patients with a narrow range of preexisting anti-DENV antibody titers (17, 18). The gene discussed is IFNAR2; the disease is dengue disease.