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:Many effects of NSAIDs are mediated via cyclooxygenase (COX)-independent mechanisms;([36]) indeed, previous studies have demonstrated that ibuprofen and other NSAIDs are agonists of PPARγ.([21-23]) On the other hand, the major metabolite of arachidonic acid via COX in VSMCs is PGF2α.
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