In order to exclude gene responses that were specific to the HepG2 cell line alone, we decided to test the expression level of these genes in the A549 cell line using the same LDA. In the A549 infection model, plaque assay revealed that peak viral production occurred earlier than in the HepG2 model (1.1610 5 61.4610 4 pfu/ ml at 48 hrs) but was still substantial at 72 hrs post-infection (7.3610 4 63.8610 4 pfu/ml). The quantitative PCR also revealed a higher number of differentially expressed genes, with 63 genes at the 48 hr time point and 82 genes at the 72 hr time point (Table S2 ).