Decreased expression of BAFF receptors on preterm cord blood–derived naive B cells compared with adult naive B cells. Freshly isolated naive B cells were assessed for the surface expression of BAFF-R, BCMA, and TACI by flow cytometry. Data are shown as mean (± SEM) of 10 independent experiments using 10 independent adult (AB), cord (CB), or preterm cord (PreCB) blood samples with each assay performed in triplicate. Statistically significant differences are shown. *P < .001; **P ≤ .005.