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:Otherwise numerous CCK2 agonists, including Boc– CCK-4, BC197 (Derrien et al. 1994; Ladurelle et al. 1997) and compound 1 (Boc-Trp-NMeNle-Asp-Phe-NH2, I. Léna, personal communication), exert a “CCK2A” pharmacological profile, essentially characterised by anxiogenic properties.
Category: