T- and B-cell zones in the LckOM LN. Sections from B6 thymus and LN and from LckOM LN were stained with hematoxylin-phloxin or labeled with antibodies specific for CD4, CD8, and B220. C indicates thymic cortex; F, B-cell follicle; and M, thymic medulla. The text to the right of the panels indicates the magnification for each row.