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:We reasoned that drugs that alter chromatin, such as 50Aza and TSA, might be effective at disrupting Cdkn1c expression when epigenetic marks are consolidated (Bhogal et al., 2004; Umlauf et al., 2004).
Category: