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:These results are supported by previous published data highlighting that the miR-34 family, including miR-34a and miR-34b/c, acts as a tumor suppressor, able to inhibit different human tumor growth and invasion [36–39], including human LSCC [31–34].
Category: