Model of the pathophysiological background of 5 B-cell patterns in CVID patients based on proliferation history and SHM levels. (A) Healthy peripheral B-cell development. Green curved arrows depict healthy B-cell proliferation. (B-F) abnormal peripheral B-cell development in the 5 B-cell patterns. Top left side: proposed pathophysiology and corresponding B-cell pattern. Red straight arrows depict decreased subset size (arrow pointing downward). T-shaped red bars depict a proposed block in B-cell development. (B) Red curved arrow depicts increased proliferation of naive B cells. (C) Red interrupted curved arrows depict decreased proliferation of marginal zone–like B cells.