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:This process is controlled not only by the protein-coding segments of the genome but also by non-coding regions, including loci that produce small RNAs (Grivna et al., 2006; He et al., 2009; Thomson and Lin, 2009).
Category: