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:…with a number of regulatory factors, including the putative Rab7 GTPaseactivating protein TBC1D5 (Seaman et al., 2009; Harbour et al., 2010), and retromer tubule formation is reported to be maximal at the time of Rab5-to-Rab7 conversion (Cullen and Korswagen, 2012; van Weering et al., 2012).
Category: