In line with the absence of IgG antibodies, there was also a loss of both P. chabaudi-specific IgG antibody-secreting-cells (ASC) in the BM (Fig 7 D), and of P. chabaudi-specific IgG MBC in the spleen (Fig 7 E) at day 32 post-infection in both Il21-/- and Il21r-/- mice when compared with WT C57BL/6 controls. Here, IL21 is linked to infection.