CD20⁺ CLL cells accumulate within HEV pockets in CLL LNs. Four-color confocal images showing the accumulation of CD20⁺ CLL cells (light blue) within HEV pockets (arrowheads) in CLL LNs. HEV endothelial cells were stained with MECA-79 (green) and CD31 or von Willebrand factor (vWF; red). Counterstaining was done with DAPI (dark blue). HEV pockets were found to house up to 4 CD20⁺ CLL cells. 63×, zoom 3; scale bar, 5 µm.