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:5); Severe proliferation defects and general growth retardation
NR Lagger et al. 2002; Kim et al. 2008; Bardai et al. 2012; Kim and Bae 2011
HDAC 2 Nucleus Die within 24h after birth; Severe cardiac defects Enhanced memory, LTP Montgomery et al. 2007; Guan et al. 2009; Kim and Bae 2011; Morris et…
Category: