With regard to dengue infection, gene expression studies have been carried out in infected human umbilical vein endothelial cells (HUVECs) by differential display reverse transcription (DD-RTPCR) and Affymetrix oligonucleotide microarrays [12] . Genes having a role in the IFN antiviral response and immune defense such as 29-59 oligoadenylate synthetase (OAS), myxovirus protein A (MxA), TNFa, galectin-9, phospholipid scramblase 1 and human inhibitor of apoptosis-1 (IAP1) were shown to be upregulated upon infection [12] . Infection with dengue of a more transformed HUVEC-like cell line, ECV304, was analyzed by a different microarray system containing 7600 cDNA oligonucleotides [13] . In this study, the expression of 15 genes involved in cell cycle, apoptosis, membrane trafficking and cytoskeleton was found to be altered after infection [13] . Using a different gene expression approach, primary macrophages infected with a clinical isolate of dengue were analyzed by a cytokine array containing 375 human cytokine-related genes with approximately 20 genes observed to be either up-or down-regulated [14] . However, the functional importance of these changes, if any, was not studied [14] .