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:As shown recently, a different member of the Krueppel-like factor family KLF4 demonstrated a potent antiapoptotic effect upon HDACi treatment which was mediated in part by direct binding and transcriptional upregulation of p57 followed by inhibition of the stress response phosphorylation pathway [42].
Category: