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:It was shown, for example, that the transcription and translation of genes that participate in antioxidant machinery (8), DNA repair, and cell cycle regulation are required for the adaptive response in human lymphocytes and fibroblasts (9, 10).
Category: