PIR and infection: Previously, we have shown that P. chabaudi parasites transmitted to mice via the mosquito vector are transcriptionally modified in asexual blood-stage parasite (Spence et al., 2013), and S7 pir genes are transcriptionally upregulated during the acute-phase of infection, whereas the chronic-phase is mostly dominated by the L1 pirs (Brugat et al., 2017).