Before revision:  Our model naturally predicts that successful integration events occur more often within more flexible or highly bent DNA, in agreement with long-standing observations. We further find that large-scale URLanisation biases integration events towards transcriptionally active genomic regions.
After revision:  Our model naturally predicts that successful integration events occur more often within more flexible or highly bent DNA, in agreement with long-standing unexplained observations: we show that HIV integration is favoured in nucleosomal rather than naked DNA, and in flexible over rigid DNA. We find that these biases arise due to the difference in the bending energy barrier associated with DNA insertions. By coupling our model to a well-established framework for large-scale URLanisation biases integration events towards transcriptionally active genomic regions.