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:…regions of bean hypocotyls correlates with the expression levels found for the PRP2 transcript in soybean
seedlings (Hong et al. 1989), in agreement with the similarity of p33/p36 with the protein deduced from the PRP2 cDNA sequence and their immunological relationship (García-Gómez et al. 2000).
Category: