Figure 1: Mechanisms involved in viral interference/persistence. The JAK-STAT and Toll pathways represent the innate immune system. Viral RNA-dependent RNA polymerase (RdRP) and cellular Retrotransposon Retrotranscriptase (RRT) through Dicer-2 are involved in the generation of viral defective genomes which are able to compete for viral and cellular factors required for translation and/or replication of the parental virus. The viral cDNAs generated by the RRT could inhibit viral replication through Dicer-2 and the RNAi pathway. RISC, RNA-induced silencing complex.