STAT1 and viral infectious disease: Importantly, although viral infections did not significantly alter total STAT1 levels, for both of the SUIT-2-passaged viruses in the SUIT-2 and HPDE cell lines, as well as both of the fibroblast cell lines, there was an increase, rather than decrease, in STAT1 phosphorylation in VSV-p53-CC (SUIT-2)- and VSV-p53wt (SUIT-2)-infected cells (Fig. 7).