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:…that the activation of mTOR signaling is necessary for the increases in protein synthesis and muscle mass that occur in response to elevated mechanical loading (Bodine et al., 2001; Drummond et al., 2009; Goodman et al., 2011a; Gundermann et al., 2014; Hornberger et al., 2004; Kubica et al., 2005).
Category: