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:…is known to be induced by Ras and repressed by p53 signaling (Li et al. 2008) and is involved in the inactivation of extrinsic as well as intrinsic apoptosis pathways, by interacting with pro-apoptotic proteins like p53, Bcl-2, Bax, Bad, PUMA, MSH2, MSH6 and others (Ludwig-Galezowska et al. 2011).
Category: