How do the right cells get to the right place in lymph nodes? It is known that lymphocytes known as B cells (that originate in the bone marrow) migrate to follicles within the nodes, whereas T cells (that originate in the bone marrow and migrate to the thymus gland) reside in an adjacent region known as the paracortex. By combining confocal, electron, and intravital microscopy, Marc Bajénoff, Jackson Egen, Lily Koo, Jean Pierre Laugier, Frédéric Brau, Nicolas Glaichenhaus, and Ronald Germain have demonstrated a role for the stroma of the node in directing these cells to the appropriate location. The stromal cells that are critical in the B cell follicles are follicular dendritic cells (FDCs) and in the paracortex it's the fibroblastic reticular cells (FRCs).