Serum-starved HFFs were inoculated with 1000 particles/cell of DgB, DgD or DgH entry-defective HSV-1 virions. Total RNA was isolated immediately after inoculation, corresponding to 0 hpi, and 6 hpi. Changes in gene expression associated with the activation of signalling pathways were identified by comparison to the transcript abundance at 0 hpi. The results from duplicate experiments indicated that downstream gene targets of a number of signalling pathways are differentially expressed above the twofold threshold after virion binding (Table 1) . These preliminary results were then used as the basis of quantitative PCR studies.