Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:Interestingly, recent reports have shown that DSBs are transiently induced during transcriptional initiation by nuclear hormone receptors and other transcription factors through a mechanism that involves topoisomerase II beta (TOP2B) (4-7).
Category: