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:Since starvation is thought to be one of the main dormancyinducing stresses encountered by Mtb inside the granuloma [11,33], Mtb WT and Dfcr mutants were starved in PBS to determine the role of the fcr genes in wax synthesis under this dormancy-inducing stress.
Category: