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:A novel prokaryotic immunity-like system (CRISPR/CAS) has been recently discovered (Barrangou et al., 2007; Brouns et al., 2008; Marraffini & Sontheimer, 2008), involving two main constituents: (i) clusters of regularly interspaced short palindromic repeats (CRISPR) and (ii) CAS (CRISPR-associated…
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