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:The leader appears to promote transcription towards the repeats (Brouns et al., 2008; Hale et al., 2008; Lillestøl et al., 2006, 2009; Marraffini & Sontheimer, 2008), generating the RNAs that constitute the molecular base of the interference action (Brouns et al.
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