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:Failure to restart telomeric replication forks, due to Ctc1 loss, has been shown to lead to an increase in fragile telomeres, stochastic and accelerated telomere attrition, an increase in single-strand G-rich telomeric DNA, and a dramatically shortened replicative potential (Gu et al., 2012).
Category: