STAT1 and infection: In an early ISG (IFN-stimulated gene)-overexpression screening, Schoggins et al. observed that infection by Yellow Fever Virus (YFV) and Dengue Virus (DENV) is enhanced in STAT1-/- fibroblasts, but to a less extent in Huh7.5 cells; this again emphasizes the cell type-dependent phenotype of LY6E as discussed above for HIV-1 [25,26].