Assertion: lymph node's region | /r/CapableOf | serve as the site
Facets:
Source sentences:
text: The thymus is composed of several regions including an outer cortex region with immature T-cells a network of epithelial cells, dendritic cells, and macrophages a corticomedullary region that serves as the site for positive selection of T-cell receptor development negative selection against autoimmune T-cells an inner medullary region containing mature T-cells epithelial reticular cells