IGHJ gene and IGHV family usage. IGHV family and IGHJ genes were identified from the Ig gene sequences using V-QUEST.²⁴  (A) The relative frequency of 6 IGHJ genes, and (B) 7 IGHV gene families in transitional (IgD⁺CD27⁻CD10⁺, n = 433), naive (IgD⁺CD27⁻CD10⁻, n = 662), switched memory (IgD⁻ and either IgG⁺ or IgA⁺, n = 1293) and IgM memory (IgD⁺CD27⁺, n = 1209) populations. “m,“ “s,” “n” and “t” indicate significant differences compared with IgM memory, switched memory, naive, and transitional cells, respectively. *P < .05; **P < .005; ***P < .0005.