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:In this sense, our results agree with previous studies reporting decreased binding levels (Oviedo et al., 1993; Rodriguez de Fonseca et al., 1994; Romero et al., 1997b), receptor activation of GTP-binding proteins (Sim et al.
Category: