Figure 1. Two models for transcriptional silencing in the presence of DSBs. In the first model, repressive chromatin structure induced by DSBs leads to inhibition of RNAP II elongation. In the second model, a phosphorylation event at the vicinity of the break mediated by DNAPKcs leads to the release of the RNAP II complex from the gene and promoter and thus inhibition of transcription elongation and reinitiation.