Evidence is emerging that geminiviruses and plant pararetroviruses can interact with the gene silencing system either from introduced DNA constructs or during viral pathogenesis. Some observations suggest there are complex relationships between DNA viral activity, transcriptional and post-transcriptional gene silencing mechanisms. (biotech-info.net)

The biggest challenges in the field at the moment are understanding two things: how does DNA methylation participate in gene silencing (and that includes what molecules target the DNA methylation to these promoter regions), and why is the cancer cell doing this? (The Thomson Corporation)

In 2005, Pikaard and his collaborators published research showing that the major function of Pol IV is to generate siRNAs, thereby singling out this RNA polymerase as a potential player in gene silencing. (ScienceDaily LLC)