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:…P450 1A5 was immunoinhibited (reflecting the contribution of 3A37 only), TLMs produced exo-AFBO and AFQ1, best fitted by sigmoidal kinetic Hill plot in agreement with the previous reports for AFB1 metabolism catalyzed by human P450 3A4 (Ueng et al., 1995) and turkey P450 3A37 (Rawal et al., 2010b).
Category: