In addition to evoking cytokine responses, viruses are known to upregulate the expression of select cellular growth factors, including insulin-like growth factor binding protein 6 (IGFBP6), which has been shown to be upregulated during HHV-6A infection (24), and vascular endothelial growth factor-C (VEGF-C), which was shown to be upregulated in HHV-1 (a.k.a., HSV-1) infection (25). This evidence concerns the gene IGFBP6 and infection.