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:Since Akt2 is known to be required for M1 polarization [51], it is possible that miR-155-mediated suppression of Inpp5d/S and Ptprj in M1(LPS + IFN-γ) macrophages promotes Akt2 signaling.
Category: