Limited N-nucleotide insertions in complete V_H-DJ_H and Vκ-Jκ gene rearrangements of cultured CD19⁺CD127⁺ and CD19⁺CD127⁻ cells. Bar graphs show the number of N-nucleotides (y-axis) in D_H-J_H (A), V_H-D_H (B), and Vκ-Jκ (C) junctions. Values represent the means ± SD of multiple sequences from FACS-purified CD127⁺ and CD127⁻ populations from 3 donors, normal cord blood B cells (NCB) from 2 donors, and FACS-purified pediatric pro-B and pre-B-cell populations from 2-3 donors. The nonparametric Mann-Whitney test was used to calculate significance levels between paired populations (horizontal bars). *P < .05; **P < .01; ***P < .001.