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 Drosophila, Pk physically interacts
D E V E LO
P M
E N T
with and clusters Vang at the apicolateral membrane, and this behavior promotes Vang accumulation on the proximal side of cells in the wing epithelium (Bastock et al., 2003; Jenny et al., 2003).
Category: