Analysis of the MHV68 infected (YFP+) plasma cell population showed that, although there were significantly fewer total infected splenocytes in IL-21R-/- mice (Fig 1), approximately 20% of infected splenocytes in both wt and IL-21R-/- mice had a plasma cell phenotype at day 14 post-infection (Fig 2C and 2D). Here, IL21R is linked to infection.