CXCL1 and infection: Notably, compared with S. aureus-infected WT mice, similarly infected RBP-J CKO mice had lower percentages of splenic neutrophils at 3, 6, and 24 h post-infection (Figure 3C and Supplementary Figure 3), suggesting that CXCL1/CXCL2 released by MZ B cells may recruit neutrophils in the early phase of systemic S. aureus infection.