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:The modulation of Notch levels in LSC/CSC derived from Tax-transgenic mice suggests that Notch may contribute in the development of ATLL similar to its role in other T-cell malignancies such as T-ALL [133,134].
Category: