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 hydrophobic motif (HM) site, respectively (Meili et al., 1999; Kamimura et al., 2008; Kamimura and Devreotes, 2010; Cai et al., 2010; Liao et al., 2010).
Category: