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:Division of Arabidopsis thaliana Proteins into Families using PFAM
Each probeset in the Affymetrix ATH1 microarray platform was mapped using BLAST (Altschul et al., 1990) to the
Table 3.
Category: