(a,b,c) ROI 1(a) first section stained for CD34 (brown) and for CD 271 (blue), (b) overlay of all 24 registered sections, (c) first frame of video of the 3D model(d,e,f) ROI 2(d) first section stained for CD34 (brown) and for CD 271 (blue), (e) overlay of all 24 registered sections, (f) first frame of video of the 3D model(g,h,i) ROI 3(g) first section stained for CD34 (brown) and for CD 271 (blue), (h) overlay of all 24 registered sections, (i) first frame of video of the 3D modelCD271 is most strongly expressed in stromal capillary sheath cells. FDCs in follicles, FRCs in a PALS and ubiquitous interstitial fibroblasts are also positive. Staining of red pulp sinuses for CD34 and of ubiquitous fibroblasts for CD271 has been reduced by choosing an appropriate iso-value.(g), (h) and (i) show two follicles (f in h) and a part of a PALS in between. Internal capillaries arise from a central artery in the PALS (asterisk in h).All scale bars = 100 μm.