Increased integrin expression correlates with increased numbers of proliferating B cells in healthy and CLL LNs. (A) Representative images of a secondary follicle in a healthy reactive LN. Proliferating germinal center B cells exhibit higher expression of CD11a, CD18, CD29, and ITGB7 than mantle zone B cells. (B) Across LN biopsies from all cytogenetic groups, the presence of higher numbers of proliferating cells correlated with increased expression of CD11a, CD29, and ITGB7, but not CD18. (C) Representative images of CLL LN biopsies without proliferation centers. Biopsies with high numbers of Ki67+ proliferating cells have increased expression of CD11a compared with biopsies with low numbers of Ki67+ proliferating cells. The increased expression of CD11a in biopsies with high numbers of Ki67+ proliferating cells was due to increased staining of the CD79a+ cells.