IFNA1 and infection: We combined DENV2 infection with chemical mutagenesis and IFN promoter induced-EGFP screen to recover DENV2 mutants with in vitro characteristics similar to the attenuated phenotype of DENV2 PDK53—the formation of small plaques on a plaque assay due to type-I IFN restriction in virus dissemination despite rapid viral RNA replication rate—as previously defined [3,6].