BIRC5 and neoplasm: Notably, all the oncolytic adenoviruses in this study were designed with Δ24E1a 39 under a tumor specific promoter (survivin promoter) 40 to ensure the tumor-specific replication of the viruses, demonstrating no significant toxicity in normal cells in vitro (Figure 2A, 6A) and no obvious damage to the liver of virus-treated mice (Figure 2 D, 7F).