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:20] In addition, several lines of evidence indicate that NSAIDs, including ibuprofen, have the ability to activate PPARγ receptors in several cell types and tissues.([21-23]) Here, we confirm that ibuprofen inhibits proliferation and report for the first time that ibuprofen inhibits migration of human coronary artery smooth muscle cells (HCASMCs), and that this correlates with the induction of a differentiated phenotype in these cells.
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