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:This N-acetylation reaction is described as a detoxification reaction since it decreases the reactivity of the primary amine function and leads, in general, to poorly “toxic” or even “innocuous” metabolites (Hein et al. 2000; Kim and Guengerich 2005; Turesky and Le Marchand 2011).
Category: