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:The activity-dependent increase of G-CSF concentration, which we have shown in the present work, supports the notion that increased cell numbers were the result of an increased mobilization from bone marrow, as G-CSF is probably the most potent progenitor cell mobilizing cytokine (11).
Category: