IFNB1 and neoplasm: However, when NC tumor cells were pretreated with IFN-β for 16 h, SRB assays at 96 hpi revealed that the potent oncolytic activity of T-VEC was almost completely impaired when compared to the IFN-β-untreated control (Figure 3A and Supplementary Figure S1), albeit depending on the NC cell line studied.