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:vivax) exhibited proline racemase activity and B-cell mitogenicity, inducing polyclonal activation, delayed specific immune responses to parasite antigens favouring parasite immune evasion, and concomitant increase of parasitemias in the early phase of infection [7-12].
Category: