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:Mammalian Rap1 isoforms are perhaps best known for regulating integrinbased cell matrix adhesion (Bos, 2005; Kim et al., 2011), but Rap1 also regulates cell–cell AJs in both Drosophila and mice (Kooistra et al., 2007; Boettner and Van Aelst, 2009).
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