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 previous studies, the L791P mutation did not affect the ability of BCAR1 to promote SRC activation and COS cell migration (30), whereas the L791D mutation partially reduced the BCAR3-dependent increase in the hyperphosphorylated BCAR1 upper band (39) and BCAR3-dependent SRC activation (51).
Category: