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:In denervated muscle, elevated
HDAC4 has a dual role: it represses muscle structural gene tran-
scription (Cohen et al., 2009) but also induces genes involved in
synapse formation andmuscle atrophy (Cohen et al., 2007; Mor-
esi et al., 2010; Tang et al., 2009).
Category: