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:…substantial evidence for an evolutionarily conserved function for the yeast and mammalian retromer complexes in regulating retrieval of TGN resident cargo from endosomes (Horazdovsky et al., 1997; Seaman et al., 1997; Seaman et al., 1998; Arighi et al., 2004; Seaman, 2004; Carlton et al., 2004).
Category: