The initial microarray screen was uninformative with respect to interferon signalling, but this was of interest because soluble gD has been reported to induce IFN [29] , while, in contrast, ISG induction is reported to require virion entry but not de novo protein synthesis [30] . Primers were designed to Type I interferons, a (IFNA1) and H (IFNB1), and the newly designated Type III interferon l (IL29). Human fibroblasts do not produce interferon gamma. Additionally, the cDNA preparation was used to identify any change in the abundance of ISGs. Both DgB and DgH virions were able to stimulate the up-regulation of IFN-a expression 2.81 fold and 2.34 fold, respectively, with a high degree of statistical significance (p#0.05) ( Table 4 ). HSV-1 particles lacking gD were unable to do so, with a fold change of 21.11 and a p = 0.15 (Table 4) .