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:Previously published results have also suggested interdependence between PI3 K/Akt/mTOR and Raf/MEK/ ERK signaling [41], and another study showed that inhibition of PI3 K or mTOR reduces the level of ERK Tyrphosphorylation in vascular smooth muscle under hyperglycemic conditions [42].
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