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:Database and online tools: Polymorphism Phenotyping (PolyPhen) [25-27] and Sorting Intolerant From Tolerant (SIFT) [28] were used to evaluate the potential pathogenicity of sequence alterations at the protein level.
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