In addition, our findings about an altered numerical distribution of distinct maturation-associated subsets of immature B-cells and mature naive B-lymphocytes in CVID, suggest potential (co)existence of maturation blockades at the earliest stages of maturation of peripheral immature B-lymphocytes, with an abnormally increased differentiation toward less reactive CD21- naive B-cells, that might finally lead to decreased plasma cell and switched memory B-cell counts in these patients. The gene discussed is CR2; the disease is common variable immunodeficiency.