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:…absence of telomerase function has been shown to lead to a senescence-associated increase in genome instability in both haploid and diploid strains (Chen and Kolodner, 1999; Hackett et al., 2001; DuBois et al., 2002; Hackett and Greider, 2003; Mieczkowski et al., 2003; Meyer and Bailis, 2007).
Category: