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:All rights reserved. doi:10.1016/j.expneurol.2007.06.029
interaction resulting in dedifferentiation of the Schwann cells and activation of a growth promoting phenotype (Hall, 2005).
Category: