We previously found that two flaviviruses, Japanese encephalitis virus and DENV-2, trigger type I IFN transcription through an RIG-I-dependent signaling cascade to activate interferon regulatory factor (IRF) and NF-kB. However, JEV induced higher activation of IRF3 and NF-kB than DENV-2 in human A549 cells [12] . Furthermore, type I IFN production triggered by doublestranded RNA (dsRNA) stimulation was blocked in DENV-2infected human DCs [13, 14] . Microarray results from rhesus macaques also indicated that type I IFN, interleukin 10 (IL-10), IL-8, IL-6 and tumor necrosis factor a (TNFa) were not upregulated with DENV-1 infection [15] . Therefore, DENV-2 might modulate the induction pathway of type I IFN and other cytokines.