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:FCCP is a proton ionophore that 1) depolarizes DCm by dissipating the H 1 gradient across the inner membrane of mitochondria (11, 12, 19), 2) releases Ca(21) from the mitochondria into the cytosol (11, 12, 19, 36, 64), and 3) inhibits ATP production by uncoupling oxidative phosphorylation (23).
Category: