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:Our results showing GFP and Bt-R1a expression in S2 cells supports previous reports that baculovirus immediate early promoters function in S2 cells (Banks et al., 2003; Vanden Broeck et al., 1995).
Category: