B cell migration in response to chemokines. Peripheral blood mononuclear cells (PMBCs) from healthy donors were cultured in the presence of various concentrations of CCL20, CCL19, CCL21, or CXCL12 for two hours. The cells migrated through ECV304-coated transwells were stained with CD19 and CD27, and the numbers of cells were assessed. The percentage of migrated cells was calculated by dividing the number of migrated CD27- or CD27+ B cells by the number of total cultured CD27- or CD27+ B cells for six to seven donors. (a) Values are mean ± standard error of the mean. *P < 0.05, **P < 0.01, ***P < 0.005, vs no chemokine. (b) Each symbol represents an individual subject. *P < 0.05, **P < 0.01, ***P < 0.005, ****P < 0.0001.