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:In line with these results, the present study showed
that n-3 PUFA supplementation up-regulated the expres-
sion of PPARa, CPT1, p-AMPK, and AMPK in liver and/ or skeletal muscle of OVX rats.
Category: