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:Reagents
IAP antagonists (IAP-As) LBW242 and LCL161[25–27] were kindly provided by Novartis Pharma Ag and solubilized in 100 % DMSO at 10 mM.
Category: