MCL1 and coinfection: Interestingly, N protein promoted the replication of influenza A virus (IAV), Dengue virus (DENV-2) and Zika virus (ZIKV), by enhancing MCL-1 protein level and exacerbated the death of IAV-infected mice, while such regulations were blocked by S63845, a specific inhibitor of MCL-1.34 Altogether, this work revealed a distinct molecular mechanism via which N protein promoted virus replication by regulating the apoptosis pathway and provided new insights into the viral replication regulation, co-infection and pathogenesis.