Steady-state CCR10⁺ plasmablasts can migrate toward CCL28 and CXCL12. Spontaneous in vitro migration toward ligands of CXCR4, CCR9, CCR10, and controls is shown for blood CD19⁺/CD27^high plasmablasts/plasma cells in steady state (A), 7 days after tetanus/diphtheria vaccination (B), and for CD38^high bone marrow plasma cells (C). Migration in controls assays was less than 1%. Each bar represents the frequency of migrated plasmablasts of one donor. nd indicates not done. (D) Steady-state CD19⁺/CD27^high plasmablasts migratory toward CCL28 or CXCL12 were stained for surface IgA and CCR10.