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:Furthermore, it is also known that Ras protein promotes ARC production and hinders its degradation (Hassen et al. 2012; Li et al. 2008; Ludwig-Galezowska et al. 2011; Green and Kroemer 2009; Foo et al. 2007)
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et al. 2005).
Category: