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 Arabidopsis, two alternatively spliced isoforms of ABI3, ABI3-a and ABI3-b have been shown to encode the fulllength and truncated ABI3 proteins, respectively (Sugliani et al. 2010).
Category: