The localisation of PIR proteins within P. chabaudi-parasitised erythrocytes during the acute- and chronic-phases of infection was investigated, using rabbit polyclonal antisera that were generated against 20-conserved residue sequences of the S7 (acute-associated) and of L1 (chronic-associated) PIR clades, respectively (Freitas-Junior et al., 2000; Otto et al., 2014), the two major pir clades expressed in P. chabaudi blood-stage parasites (Brugat et al., 2017; Little et al., 2021). Here, PIR is linked to infection.